Lubricant compositions and methods

ABSTRACT

Abstract of Disclosure 
     A process is disclosed for manufacturing a lubricant composition comprising combining a superabsorbent polymer with a material for decreasing friction between moving surfaces.  The superabsorbent polymer absorbs from about 25 to greater than 100 times its weight in water and may comprise a polymer of acrylic acid, and acrylic ester, acrylonitrile or acrylamide, including co-polymers thereof or starch  graft copolymers thereof or mixtures thereof.  A product produced by the process includes the material for decreasing friction comprising a petroleum lubricant containing an additive, water containing an additive, synthetic lubricant, grease, solid lubricant or metal working lubricant, wherein the synthetic lubricant, grease, solid lubricant or metal working lubricant optionally contain an additive.  A process comprising controlling the delivery of a lubricant to at least one of two moving surfaces in order to decrease friction between said moving surfaces, is also disclosed.  This process includes applying the lubricant composition to at least one of the surfaces.  The lubricant composition in this instance comprises a superabsorbant polymer combined with a material for decreasing friction between moving surfaces, wherein the material for decreasing friction comprises a petroleum lubricant, water, synthetic lubricant, grease, solid lubricant or metal working lubricant, and optionally an additive.

[0001] This application is a divisional of U.S. Application Serial No.08/943,123, filed October 3, 1997, which is a continuation-in-part ofU.S. Application Serial No. 08/487,436, filed June 7, 1995, the contentsof which are incorporated herein by reference in their entirety

[0002] Field of the Invention

[0003] The field of the invention is lubricants and especially lubricantcompositions comprising a superabsorbent polymer in combination with alubricant material.

[0004] Description of the Related Art

[0005] Lubricant materials function by separating moving surfaces tominimize friction and wear. Archeological evidence dating to before 1400B.C. shows the use of tallow to lubricate chariot wheel axles. Leonardoda Vinci discovered the fundamental principles of lubrication andfriction, but lubrication did not develop into a refined science untilthe late 1880's in Britain when Tower produced his studies on railroadcar journal bearings in 1885. In 1886 Reynolds developed this into atheoretical basis for fluid film lubrication.

[0006] Lubrication principles vary from the separation of movingsurfaces by a fluid lubricant through boundary lubrication, to drysliding. In many respects, these principals are coextensive.

[0007] Fluid Film Lubrication

[0008] In fluid film lubrication, the load on moving surfaces issupported entirely by the fluid between the surfaces which is a filmunder pressure. The pressure on the film develops through the motion ofthe surfaces, which in turn delivers the lubricant into a convergingwedge-shaped zone. The behavior of the moving surfaces is totallydependent on the fluidity or viscous behavior of the lubricant. Filmpressure and power loss are dependent on the viscosity of the lubricantas well as the configuration of the moving surfaces, and lubricant shearstrength. Hydrodynamic or squeeze-film action cannot provide adequateload support in some instances for bearings lubricated with oil orwater. Pumping the lubricant into the moving surfaces sometimes providesthe necessary hydrodynamic or squeeze-film properties for bearings usedfor handling heavy loads in low speed equipment. This practice isespecially common with low viscosity lubricants such as water. It wouldtherefore be advantageous to provide additives to these types oflubricants to overcome these difficulties.

[0009] Oil film lubricants on surfaces are limited in their lubricatingcapabilities and as such have load limits. Asperities or high spots onthe moving surfaces will in turn support the load when the load limit ofthe lubricant is reached so that the lubrication moves from full-film tomixed-film to complete boundary lubrication with an increase incoefficient of friction between the moving surfaces. High load, lowspeed, low viscosity lubricants, misalignment, high surface roughness oran inadequate supply of lubricant causes this change from full-film toboundary lubrication. Chemical additives, however, can reduce resultantwear and friction.

[0010] Surface contact through asperities on the moving surfaces canresult in tearing of the surfaces and is especially a problem withincreasing loads. Plastic deformation, temperature buildup and weldingof the surfaces with eventual seizure of the surfaces occurs as aresult. This problem is especially prevalent in hypoid gears used inautomobile differentials. Extreme pressure lubricants combat welding ofthe surfaces in these circumstances and contain organic compounds thatreact at these elevated temperatures and form high-melting inorganiclubricant films on the surfaces. Sulfur, chlorine, phosphorous and leadcompounds in these additives provide low shear strength layers thatminimize surface tearing, or coat the moving surfaces to prevent fusing.Since extreme pressure additives function by chemical action, they arenot used where the metal surfaces will be severely eroded. Increasingthe lubricant or oil viscosity by means of an additive, lowering theunit bearing loading, improving the finish on the moving surfaces anduse of external pressurization offer alternatives to extreme-pressureadditives.

[0011] Dry rubbing or dry sliding involving solid-to-solid contactoccurs in fluid lubrication systems as for example in machine start-up,run-in misalignment or inadequate clearance, reversal of direction ofmoving surfaces, or any unforeseen or unplanned interruptions inlubricant delivery. Conventional lubricants such as greases or oils alsoare not used on moving surfaces in extreme temperature, high vacuum,radiation or contamination environments. Dry lubricants applied as thincoatings or as particulate materials in these environments reduce wearand friction of moving surfaces. These films or particulate materialsmay comprise or incorporate solid or particulate carbon-graphite, leadbabbitt, bronze, aluminum, polyethylene or polytetrafluoroethylene solidor particulate materials in a binder where the film or particulates areadhered to one or both of the moving surfaces. The effectiveness of thedry lubricant film or particulates is controlled to some degree by thebinder where solid or particulate lubricants are employed as well asconditions of use such as the load, surface temperatures generatedduring use, speed of the moving surfaces, hardening, fatigue, welding,recrystallization, oxidation and hydrolysis. It would be an advantagetherefore to have a binder that is strongly adherent and resistant tosome of the conditions generated while in use.

[0012] In elastohydrodynamic lubrication carrying the load on rollingcontacts in ball and roller bearings, gear teeth, cams or frictiondrives, minimizes lubrication problems. Focusing the load on a smallcontact area on these moving surfaces results in high elastic contactstresses. Lubricant films help support the load which is described as"elastohydrodynamic," because of the close relationship between theformation of a thin hydrodynamic fluid lubricant film and elasticdeformation.

[0013] The lubricant viscosity and film conditions at the entry of thecontact zone in these systems generally fix the lubricant film thicknesswhich is substantially uniform over most of its length along thecontact. It is believed that high contact pressures lead to excessivelubricant viscosity and pressure distribution close to the Hertz patternfor simple static elastic contact theory. It has also been noted thatonly a slight reduction in film thickness results with increasing loadswith pronounced contact deformation. In plotting contact pressure in psi(pounds per square inch) against distance and direction of lubricantflow, it appears that optimum lubricity is obtained with a sharppressure spike at the exit portion of the lubricant film; however, thisdoes not take into account changes in temperature, relaxation time orother variables in the lubricating system. It would therefore be anadvantage to provide an additive that would enhance viscosity and filmformation and retention under these and other conditions.

[0014] Load capacity with a full elastohydrodynamic film is limited byfatigue strength of the moving surfaces in rolling contact systems. Theworking of grain boundaries beneath the contact surface, where shearstress is at a maximum, generates damage. Fatigue cracks occur withinthis heavily stressed zone with repeated stress cycles. Particles areloosened, which is characterized as surface flaking, and represents thedepth of the zone of maximum shear stress. The fatigue cracks arestarted by focal points of oxide particles and stringers of impurities.

[0015] Where the lubricant film thickness becomes less than the surfacefinish of the moving or rolling surfaces, under high load, low speed orlow lubricant viscosity, boundary lubrication comes into play which isdependent upon the chemical nature of the lubricant. The drop in fatiguelife can be avoided under such conditions as well as surface wear withthe proper lubricant additives.

[0016] Petroleum Lubricants

[0017] Petroleum based lubricants are extensively used because of theirwide availability and consequent low cost. Petroleum lubricants are wellknown in the art and generally comprise low viscosity and low densityparaffins having relatively high freezing points. When combined withoxidation inhibitors to obtain high temperature stability, oxidationresistance is improved and sludging tendency is minimized.

[0018] Aromatic petroleum lubricants such as napthenes are generallyoxidation stable but form insoluble sludges at high temperatures.Naphthenic oils have low pour point, low oxidation stability andproperties between paraffins and aromatics. They are also present inparaffin lubricants to a small degree. Naphthenic oils, however, ornaphthenes are used by themselves in combination with oxidationinhibitors. It therefore would be advantageous to provide additives thatminimize these difficulties.

[0019] Representative petroleum lubricating oils include SAE types 10W,20W, 30, 40, 50, 10W-30, 20W-40, 75, 80,90 140, 250 and so-calledautomatic transmission fluids.

[0020] Additives

[0021] Various additives mixed with lubricating materials help meet therequirements of modern automobile engines, high-speed machinery,high-pressure hydraulic systems, torque converters, aircraft engines,turbine engines, steam engines, steam turbines, electric motors,hydraulic systems and the like.

[0022] Petroleum lubricants and other so-called oil-type lubricantsemploy sulfur, nitrogen or phosphorous type organic compounds, andalkylphenols as antioxidants or oxidation inhibitors. Hydroperoxidesinitially formed in the oil during oxidation lead to the subsequentproduction of organic acids and other oxygen containing organiccompounds. Antioxidants either inhibit the formation of, or complex,hydroperoxides to minimize the formation of acids, sludge and varnish.

[0023] Some commonly employed oxidation inhibitors for steam turbines,electric motors and hydraulic systems include 2-naphthol,di-t-butyl-p-cresol and phenyl-1-naphthylamine. Thiophosphates such aszinc, barium, and calcium thiophosphate are also widely used asantioxidants in lubricating oils for automobile and truck engines.

[0024] Alkylsuccinic type acids and other mildly polar organic acids ororganic amines are employed as rust inhibitors as well as organicphosphates, polyhydric alcohols, sodium sulfonates and calciumsulfonates.

[0025] Many antiwear compounds, generally well known in the art, improveboundary film lubrication, and are classified into seven main groups.The first comprises compounds containing oxygen, such as fatty acids,esters and ketones; the second comprises compounds containing sulfur orcombinations of sulfur and oxygen; the third comprises organic chlorinecompounds such as chlorinated wax; the fourth includes organic sulfurcompounds such as sulphurized fats and sulphurized olefins; the fifthcomprises compounds containing both chlorine and sulfur; the sixth,compounds containing organic phosphorous compounds such as tricresylphosphate, thiophosphates, and phosphites; and the seventh, organic leadcompounds such as tetraethyl lead. The use of olefins for lubricatingaluminum moving surfaces and iodine for high temperature alloys has alsobeen described in the art.

[0026] Antiwear agents employed in boundary lubricants include mildlypolar organic acids such as alkylsuccinic type acids and organic amines.Tricresyl phosphate or zinc dialkyldithiophosphate additives areemployed in lubricants for hydraulic pumps, gears and torque converterswhereas severe rubbing conditions encountered in high loadmetal-to-metal moving surfaces require lubricants and especially oiltype lubricants containing active sulfur, chlorine and lead compounds.These extreme-pressure additives enter into a chemical reaction to formcompounds on the surface of the metal moving parts such as lead sulfide,iron chloride or iron sulfide.

[0027] Detergents and dispersants are employed in lubricants andfunction by adsorption on any insoluble particles formed by the movingor sliding contact of two or more surfaces, and maintain the particlesin suspension in the lubricant. This minimizes deposits on the movingsurfaces and enhances the cleanliness of the moving surfaces. Detergentssuch as alkyl methacrylate polymers having polar nitrogen groups in theside chain are generally employed and are well known in the art.

[0028] The addition of pour-point depressants such as polymethacrylatesor wax with naphthalene or wax phenol condensation products alsoimproves the properties of lubricants.

[0029] Many lubricants also contain viscosity-index improvers such aspolyisobutylenes, polymethacrylates and poly(alkylstyrenes) having amolecular weight of from about 5000 to 20,000. The addition of foaminhibitors such as methyl silicone polymers in lubricating fluids andespecially oil type lubricants reduces frothing.

[0030] Synthetic Lubricants

[0031] Another class of lubricants comprises synthetic oils such as lowmolecular weight polymerized olefins, ester lubricants, polyglycols andsilicones, all of which are widely known in the art. Other syntheticoils include tricresyl phosphate, silicones, other organic phosphates,polyisobutylene, polyphenyl ethers, silicates, chlorinated aromatics,and fluorocarbons.

[0032] The silicone lubricants generally comprise low molecular weightpolymers or di-organo substituted silicon oxide where the organo groupsare ethyl groups, phenyl groups or mixtures thereof and are formulatedeither as room temperature liquids having the viscosity of oil orcompounded into greases. The chlorophenyl methyl silicone oils areespecially suitable.

[0033] Organic esters generally comprise diesters based on thecondensation of long chain diacids having from about 6 to about 10carbon atoms such as adipic, azelaic or sebacic acid with branched-chainalcohols having from about 8 to about 9 carbon atoms. Higher temperaturelubricants employed for turbines and especially jet engines compriseesters of trimethylolpropane or pentaerytheritol with these acids.Polymethacrylates thickening agents, sometimes added in amounts up toabout 5%, increase the viscosity of these fluids, which is somewhatlower than petroleum oils.

[0034] The polyglycol lubricants comprise those based on polypropyleneglycol prepared from propylene oxide and contain terminal hydroxylgroups. These are water insoluble lubricants. Mixtures of propylene andethylene oxides in the polymerization process will produce a watersoluble polymer, also used as a lubricant. Liquid or oil typepolyglycols have lower viscosities and molecular weights of about 400,whereas 3,000 molecular weight polyglycols are viscous polymers at roomtemperature. The use of mono- or polyhydric, such as dihydric, alcoholsin the ethylene oxide and/or propylene oxide polymerization results inthe formation of mono- or diethers which yield a different class ofpolyglycols. Esterifying the hydroxyl groups in the polyols with low orhigh molecular weight acids, i.e., those having up to about 18 carbonatoms gives another variety of polyglycol lubricants.

[0035] The polyglycols are employed in various industrial hydraulicfluid applications. They generally do not dissolve rubber and find useas rubber lubricants or as textile fiber lubricants in textileprocessing. Because they decompose into volatile products at hightemperatures they also find use in once-through lubrication systems suchas in jet aircraft engines and other high temperature operations thatwould result in depositing carbonaceous materials on the moving surfacesand consequent operational and maintenance difficulties. Combining watersoluble polyglycols with water provides compositions for use inhydraulic applications such as die casting machines, furnace controls,electric welders, and navy hydraulic catapults, as well as equipmenthandling for missiles.

[0036] The phosphate lubricants find use in fire resistance applicationsand generally comprise triaryl or trialkyl phosphates. Fire resistanceapplications include die casting machines, aircraft hydraulic fluids,air compressor lubricants and various naval and industrial systems.Blending the phosphates with chlorinated biphenyls provides hydraulicstability.

[0037] Polymerization of isobutylene containing smaller amounts of1-butene and 2-butene provides polybutylene lubricants ranging inviscosity from 5 to over 600 centistokes at 210°F with a chain length offrom about 20 to greater than about 100 carbon atoms. Polyisobutylenesfind application in high temperature apparatus such as conveyors, ovens,dryers and furnaces since they decompose and oxidize substantially toentirely volatile by-products leaving no carbon residue contrary topetroleum based lubricants. They find use in electrical transformers,cables, and refrigerator compressors with the higher viscosity gradesemployed as viscosity-index additives in petroleum lubricants.

[0038] Polyphenyl ethers or polyphenoxy polymers, with the ether groupin the three phenyl position in the polymer chain find use in hightemperature applications such as jet engines and hydraulic systems sincethey exhibit temperature stability at about 500°F.

[0039] Silicate ester high temperature hydraulic fluids generallycomprise tetra(2-ethylhexyl) and tetra(2-ethylbutyl) silicates as wellas the sodimer silicates such as hexa(2-ethylbutoxy) disiloxane.

[0040] Chlorinated bi-phenyl fluids provide fire resistance forlubricating fluids and hydraulic fluids.

[0041] Fluorocarbons such as polychlorotrifluoroethylene and copolymersof perfluoroethylene perfluoropropylene non-solid lubricants providehigh oxidation resistance in lubricating liquid oxygen and hydrogenperoxide manufacturing and handling equipment.

[0042] Greases

[0043] Greases comprise high viscosity lubricating fluids, made bycombining a petroleum or synthetic lubricating fluid with a thickeningagent. The thickeners generally comprise fatty-acid soaps of lithium,calcium, strontium, sodium, aluminum, silica gel, and barium. The greaseformulation may also include coated clays such as bentonite andhectorite clays coated with quaternary ammonium compounds. Sometimescarbon black is added as a thickener to improve high-temperatureproperties of petroleum and synthetic lubricant greases. The addition oforganic pigments and powders which include arylurea compoundsindanthrene, ureides, and phthalocyanines provide high temperaturestability.

[0044] Grease additives generally fall into the same category as theadditives employed in petroleum lubricants including amine, phenolic,phosphite, sulfur, and selenium oxidation inhibitors. Amine deactivatorsare also employed where copper staining would be a problem or wherecopper would tend to promote catalytic oxidation. Amine salts, metalsulfonates, metal naphthenates, esters, and nonionic surfactants provideadded water resistance, and some protection against salt-spraycorrosion.

[0045] Greases employed in gear applications or sliding surfaceapplications contain extreme-pressure additives such as lead soaps,sulfur, chlorine and phosphorous additives as described above. Addingsolid powders such as graphite, molybdenum disulfide, asbestos, talc,and zinc oxide provides boundary lubrication.

[0046] Glycerol stabilizes the soap structure when used in combinationwith small amounts of water as well as dimethylsilicone oil to minimizefoaming.

[0047] Formulating the foregoing synthetic lubricants with thicknersprovides specialty greases and include, without limitation, polyglycol,diester, silicone-diester, polyester, and silicone lubricants.Nonmelting thickeners are especially preferred such as copperphthalocyanine, arylureas, indanthrene, and organic surfactant coatedclays. The organic esters and the silicone greases are generallyemployed in military applications especially for high temperature use.

[0048] The mechanical properties of greases have been measured and thosematerials having a NLGI number from 0 to 6 characterize these greases.

[0049] Solid Lubricants

[0050] Solid lubricants include inorganic compounds, organic compounds,and metal in the form of films or particulate materials to providebarrier-layer type of lubrication for sliding surfaces. These materialsare substantially solid at room temperature and above, but in someinstances will be substantially liquidus above room temperature.

[0051] The inorganic compounds include materials such as cobaltchloride, molybdenum disulfide, graphite, tungsten disulfide, mica,boron nitride, silver sulfate, cadmium chloride, cadmium iodide, boraxand lead iodide. These compounds exemplify the so-called layer-latticesolids in which strong covalent or ionic forces form bonds between atomsin an individual layer while weaker Van der Waal's forces form bondsbetween the layers. They generally find use in high temperatureapplications because of their high melting points, high thermalstabilities in vacuum, low evaporation rates, and good radiationresistance. Especially suitable materials include formulated graphiteand molybdenum disulfide. Both molybdenum disulfide and graphite havelayer-lattice structures with strong bonding within the lattice and weakbonding between the layers. Sulfur-molybdenum-sulfur lattices formstrong bonds whereas weak sulfur-sulfur bonds between the layers alloweasy sliding of the layers over one another. Molybdenum disulfide andgraphite are therefore especially important solid inorganic lubricants.

[0052] The particulate solid materials are formulated as colloidaldispersions in either water, wax, wax emulsions, petroleum oil, castoroil, mineral spirits. The solid non-particulate materials may beemployed as solutions in solvents selected to dissolve the solids toform a substantially liquidus composition at room temperature. Thesesolutions in turn can be made into emulsions as described herein,especially water emulsions. Where solvents are unavailable or difficultor expensive to use, the solid lubricants are used as particulates.

[0053] The emulsions, as that term is used herein, are either water inoil or oil in water emulsions, or oil in oil emulsions where thesolution is either the continuous or discontinuous phase. Waterdispersions are used for lubricating dies, tools, metal-working molds,oxygen equipment and in wire drawing.

[0054] Graphite-water dispersion used as a lubricant lose water due toevaporation, which is a disadvantage. Mixing the graphite with cadmiumoxide or molybdenum disulfide overcomes this.

[0055] Other suitable inorganic materials that do not have thelayer-lattice structure include basic white lead or lead carbonate, zincoxide, and lead monoxide.

[0056] Dispersing the inorganic compounds in various liquids such aslower molecular weight alcohols, glycols, petroleum oils, syntheticoils, and water, provides compositions used in airframe lubrication,fastenings such as nuts and bolts or screws, gears, wire drawing, andlubricating fittings.

[0057] Solid organic lubricant compounds comprise high melting organicpowders such as phenanthrene, copper phthalocyanine, and mixtures withinorganic compounds and/or other lubricants. Copper phthalocyanineadmixed with molybdenum disulfide comprises a good roller bearinglubricant.

[0058] The metal lubricants generally comprise soft metals such asgallium, indium, thallium, lead, tin, gold, silver, copper and the GroupVIII noble metals, ruthenium, rhodium, palladium, osmium, iridium, andplatinum. Forming these metal lubricants into particulate dispersions ina fluid and especially a liquid such as a liquid lubricant as describedherein including petroleum oils, synthetic oils, and water provideseasily applied lubricant compositions. Chalcogenides of the non-noblemetals may also be employed, especially the oxides, selenides, orsulfides.

[0059] Combining the solid lubricants with various binders keeps them inplace on the moving surface. Binders are especially necessary in drylubricant applications employing solid or particulate lubricants, andare sometimes described as bonded solid lubricants. Variousthermosetting and thermoplastic and curable binder systems includephenolic, vinyl, acrylic, alkyd, polyurethane, silicone, and epoxyresins. It would be an advantage, however, to provide a novel binderthat performed in the same way or improved on the function of thesebinders.

[0060] These types of coatings find application as lubricants forfasteners and bolt assemblies. The solid lubricants employed in thelatter application usually include silver, nickel, copper, molybdenumdisulfide, lead, or graphite.

[0061] Metal Working Lubricants

[0062] Metal working is another important area of lubrication metalworking which generally comprises operations involving machining,grinding, honing, lapping, stamping, blanking, drawing, spinning,extruding, molding, forging, and rolling. The lubricants employedgenerally comprise water, mineral oils, fatty oils, and fatty acids,waxes, soaps, various chemical compounds, minerals, and syntheticlubricants as described herein. Some of the foregoing materials will beat a disadvantage because they do not have the proper stickingproperties or viscosity properties to remain in place on the metalsurfaces during working and accordingly have to be formulated to assurethat they will be in place during the metal working operation. Theaddition of synthetic polymers to these lubricants would overcome someof these disadvantages.

[0063] Lubricants are also described by Kirk-Othmer Encyclopedia ofChemical Technology, Second Edition, pp. 559-595 which is incorporatedherein by reference.

[0064] For the purpose of the present invention, all of the foregoinglubricant compounds or composition will be referred to as materials fordecreasing friction between moving surfaces or lubricants.

[0065] From the foregoing, it should be apparent that there is a needfor additional materials that will provide the same advantages as thoseof the related art as well as additional advantages and also materialsthat will overcome some of the various disadvantages of the related art.

[0066] Accordingly, the present invention is directed to a novelcomposition which includes a material for decreasing friction betweenmoving surfaces as well as a method for lubricating a surface.

[0067] Summary of the Invention

[0068] These and other advantages are obtained according to the presentinvention, which is the provision of a composition and a process toenhance the various advantages of the related art and which alsosubstantially obviate one or more of the limitations and disadvantagesof the described prior compositions of matter and processes.

[0069] The description which follows sets forth additional features andadvantages of the invention, apparent not only from the description, butalso by practicing the invention. The written description and claimshereof particularly point out the objectives and other advantages of theinvention and show how they may be realized and obtained.

[0070] To achieve these and other advantages, and in accordance with thepurpose of the invention, as embodied and broadly described, theinvention comprises a lubricant composition of matter comprising asuperabsorbent polymer combined with a material for decreasing frictionbetween moving surfaces or a lubricant as described herein. Where thelubricant is water or a petroleum oil, the composition also includes anadditive such as described herein including without limitation, anoxidation inhibitor, a rust inhibitor, antiwear agent,detergent-dispersant, pour-point depressant, viscosity-index improver orfoam inhibitor, especially those described herein.

[0071] The invention also comprises a method of lubricating a surfacecomprising coating the surface with a lubricating composition comprisinga superabsorbent polymer combined with a material for decreasingfriction between moving surfaces as described herein; however, themethod of the invention includes the use of water or oil as lubricantsas well as other lubricants either with or without additives asdescribed herein. In a further embodiment, the invention relates to thecontrolled delivery of a lubricant to a surface in order to decreasefriction between moving surfaces, by applying the lubricant compositionof the invention to at least one of such surfaces.

[0072] The invention also comprises a process for manufacturing theaforesaid lubricant composition for decreasing friction between movingsurfaces by combining a lubricant with a superabsorbent polymer. Inthose instances where the various components of the lubricantcomposition react with one another and their identity in the finalcomposition is difficult or impossible to partially or completelyascertain, a product is produced according to the invention which ismade by the inventive process. The invention, therefore, also relates toa novel product produced by the process of the invention.

[0073] The invention also relates to a process comprising controllingthe delivery of a lubricant to at least one of two moving surfaces inorder to decrease friction between said moving surfaces, comprisingapplying a lubricant composition or product produced according to theprocess of the invention to at least one of said surfaces. It isintended that applying the lubricant composition or the product producedaccording to the invention to at least one of the surfaces is to includethose instances where one, some, or all of the surfaces are stationary,or one, some, or all of the surfaces are moving, but in any event, suchsurfaces are or will be frictionally engaged with one another.

[0074] Applicant intends that controlling the delivery of the lubricantto a surface includes phenomena where the lubricant is incrementallywithdrawn incrementally, released incrementally, delivered orincrementally applied from the lubricant composition of matter or theproduct produced by the process of the invention. In another embodiment,controlling delivery can be effected by one of the surfaces skimming amicroscopic layer, and in some instances one or more molecular layers ofthe lubricant composition or product produced by the process of theinvention from at least one other surface and leaving the remainder ofthe composition or product on at least one other surface.

[0075] In another aspect of the invention, the various lubricants canact as plasticizers for the superabsorbent polymer, especially theorganic lubricants and particularly those organic lubricants that areliquids at about 15 to about 30°C. Where the lubricants comprise theso-called MORFLEX^(®), CITROFLEX^(®), and AROSURF^(®) compounds, asthose compounds are defined herein, they especially include variouslubricant additives as defined herein.

[0076] Throughout the written description and claims, the lubricantcomposition is described as a superabsorbent polymer combined with amaterial for decreasing friction between moving surfaces or lubricant,by which it is intended that the superabsorbent polymer and thelubricant either form a solution, a dispersion, or an emulsion includingboth water in oil emulsions as well as oil in water emulsions, and oilin oil emulsions wherein a solution is emulsified, and where thesolution can be the continuous phase or the discontinuous phase.

[0077] The superabsorbent polymer employed according to the invention,absorbs from about 25 to greater than 100 times its weight in water andcomprises a polymer of acrylic acid, an acrylic ester, acrylonitrile oracrylamide, including co-polymers thereof or starch graft copolymersthereof, or mixtures thereof, where the mixtures contain from 2 to about3 or 4 superabsorbent polymers.

[0078] Superabsorbent polymers that may be employed in the presentinvention comprise those generally described and those specifically setforth by Levy in United States Patents Nos. 4,983,389, 4,985,251, andparticularly those described in U.S. Patent No. 4,983,389, in column 9,lines 37-48, column 10, lines 40-68, and column 11, lines 1-21, as wellas those also described in U.S. Patent No. 4,985,251, column 9, lines1-30. The various U.S. patents to Levy, are incorporated herein byreference for their teachings relative to the superabsorbent polymers.

[0079] Other superabsorbent polymers include AQUASORB^(®) which arecopolymers of acrylamide and sodium acrylate or the potassium orammonium salts thereof; AQUASORB^(®) which are acrylamide-sodiumpolyacrylate cross-linked copolymers; AQUASTORE^(TM) which is an ionicpolyacrylamide, and cross-linked modified polyacrylamides,TERRA-SORB^(TM) which is a hydrolyzed starch-polyacrylonitrile;SANWET^(®) which is a starch-graft-sodium-polyacrylate, or apolyurethane with starch-graft-sodium polyacrylate, starch-graft-sodiumpolyacrylate, starch, polymer with 2acid, sodium salt, WATER LOCK^(®)which is a poly-2-propenoic acid, sodium salt, and a starch-g poly(2-propenamide-co-2-propenoic acid, sodium salt) or mixed sodium andaluminum salts or potassium or a 2-propenoic acid, sodium salt orpolyacrylamide-co-sodium acrylate); AQUAKEEP^(®) which is a polyacrylicacid, sodium salt, AGRI-GEL^(TM) which is an acrylonitrile starch graftcopolymer, SGP^(®) 502S which is a starch-g-poly (acrylamide-co-sodiumacrylate; STOCKOSORB^(®) which comprise acrylate/acrylamide copolymers,acrylate/polyvinyl alcohol copolymers, and polyacrylates, and thevarious sodium and potassium salts thereof, FAVOR^(®) C which is apotassium polyacrylate/polyacrylamide copolymer; XUfrom Dow Chemicalwhich is a partial sodium slat of cross-linked polypropenoic acid;ASAP^(TM) 1000 which is a reaction product of lightly cross-linkedsodium polyacrylate in water with hydrophobic amorphous silicon dioxide,and acrylic acid, ARIDALL^(®) which are sodium or potassiumpolyacrylates that may be lightly cross-linked, SANWET^(®) which is astarch grafted sodium polyacrylate, NORSOCRYL^(®) which is a poly(sodiumacrylate) homopolymer, and ALCOSORB^(TM) which is a copolymer ofacrylamide and sodium acrylate, and the various superabsorbent polymersdescribed by Takeda et al. U.S. Patent No. 4,525,527; Mikita et al. U.S.Patent No. 4,552,938; U.S. Patent No. 4,618,631; Mikita et al. U.S.Patent No. 4,654,393; Alexander et al. U.S. Patent No. 4,677,174; Takedaet al. U.S. Patent No. 4,612,250; Mikita et al. U.S. Patent No.4,703,067; and Brannon-Peppas, Absorbent Polymer Technology, 1990. Othersuperabsorbent polymers may be employed which are further described byBuchholz et al., Superabsorbent Polymers, Science and Technology, 1994ACS. All of the foregoing are incorporated herein by reference.

[0080] The invention also includes the addition of other materials tothe superabsorbent polymer to enhance its loading characteristics, andincludes hygroscopic materials such as acrylic acid copolymers (e.g.,PEMULEN^(®)TR-1), and the various inorganic or organic art knownequivalents thereof, especially the organic hygroscopic materials. Otherorganic hygroscopic materials in this respect include glycerol, and thevarious soaps, especially those described herein, and may also beemployed, as well as mixtures of hygroscopic materials, especially the 2to about 3, or about 4 component mixtures.

[0081] Mixtures of these hygroscopic materials with the superabsorbentpolymers may also be employed, especially the 2 to about 3, or about 4component mixtures.

[0082] In one embodiment, the material for decreasing friction comprisesa petroleum lubricant containing an additive, water containing anadditive, synthetic lubricant, grease, solid lubricant or metal workinglubricant, wherein said synthetic lubricant, grease, solid lubricant ormetal working lubricant optionally contain an additive. Lubricating oilsinclude either a petroleum oil or synthetic oil or synthetic organicliquid as described herein including without limitations petroleumlubricants including the paraffins, aromatics, naphthenic oils, thesynthetic oils, including the silicones, organic esters, polyglycols,phosphates, polyisobutylenes, polyphenol ethers, silicates, chlorinatedaromatics, and fluorocarbons all as described herein.

[0083] The greases, solid lubricants, and metal working lubricants arealso as described herein.

[0084] Various mixtures of each of the foregoing lubricants may be usedincluding mixtures of 2 to about 3 or about 4 lubricants.

[0085] As noted before, additives described herein are also employedaccording to the invention. The composition of matter includes additiveswhere petroleum oil or water is used as a lubricant, whereas the methodof the invention of lubricating a surface includes the use ofsuperabsorbent polymers in combination with the lubricants describedherein, with or without the additives.

[0086] The material for decreasing friction between moving surfaces orlubricant employed according to the present invention also includeswater or combinations of water and oil whether petroleum oils orsynthetic oils as those materials are described herein. When water isused in combination with oil, it generally is employed as an emulsionwhether a water in oil emulsion or an oil in water emulsion, both ofwhich are well known in the art and are manufactured by methods that aresimilarly well known.

[0087] The invention also relates to a superabsorbent polymer combinedwith a solid or particulate inorganic lubricant such as those describedherein including mixtures of solid or particulate inorganic lubricantsespecially mixtures of 2 to about 3 or about 4 solid or particulateinorganic lubricants.

[0088] In one embodiment, these inorganic lubricants comprise graphite,the chalcogenides of molybdenum, antimony, niobium, and tungsten, wherethe chalcogens comprise oxygen, sulfur, selenium, and tellurium andespecially molybdenum disulfide, cobalt chloride, antimony oxide,niobium selenide, tungsten disulfide, mica, boron nitride, silversulfate, cadmium chloride, cadmium iodide, borax, basic white lead, leadcarbonate, lead iodide, asbestos, talc, zinc oxide, carbon, babbit,bronze, brass, aluminum, gallium, indium, thallium, thorium, copper,silver, gold, mercury, lead, tin, indium, or the Group VIII noblemetals.

[0089] Chalcogenides of the non-noble metals may also be employed,especially the oxides, selenides or sulfides. In another embodiment, theinorganic solid or particulate material comprises a phosphate such as azinc phosphate, iron phosphate, or manganese phosphate, or mixturesthereof. Mixtures of the solid or particulate lubricants can be used,especially the 2 component 3 or about 4 component mixtures.

[0090] The superabsorbent polymers are also combined with a solid orparticulate organic lubricant including mixtures of the organiclubricant and especially 2 to about 3 or about 4 component mixtures.

[0091] The solid or particulate organic lubricant comprisesphenanthrene, copper phthalocyanine, a fluoroalkylene homopolymer orcopolymer such as polytetrafluoroethylene, polyhexafluoroethylene, orcopolymers of perfluoroethylene and perfluoropropylene. Homopolymers ofpolyvinylidene fluoride or copolymers of polyvinylidene fluoride andhexafluoropropylene may also be employed as well as other fluorinatedpolymers which are well-known in the art. The solid or particulateorganic lubricant may also include alkylene homopolymers or copolymerssuch as polymers of ethylene, propylene, isopropylene, butylene, andisobutylene and the various copolymers thereof especially the 2 or 3component copolymers thereof. The solid or particulate organic lubricantmay also include a paraffinic hydrocarbon wax. Various mixtures of thesolid or particulate organic lubricants may also be employed, especiallythe 2 to about 3 or about 4 component mixtures.

[0092] Combinations of the solid or particulate inorganic lubricant andthe solid or particulate organic lubricant can also be employed,especially the 2 to about 3 or 4 component combinations. Both the solidor particulate inorganic lubricant and the solid or particulate organiclubricant may also be combined with room temperature liquid materialsfor decreasing friction between moving surfaces such as oil lubricantsand/or synthetic lubricants as described herein or water or combinationsof water and oil (including the synthetic lubricants) as describedherein.

[0093] The solid or particulate inorganic lubricant or solid orparticulate organic lubricant can also be used in combination with thesuperabsorbent polymers either as a mixture of powdered super absorbentpolymer with solid or particulate organic lubricant or where thesuperabsorbent polymer is admixed with water or oil or both as describedherein.

[0094] The superabsorbent polymer is also combined with a material fordecreasing friction which comprises a metal working lubricant containingwater or an emulsion of oil and water where the oil is either apetroleum oil or synthetic oil but especially a mineral oil and theemulsion comprises either a water in oil or an oil in water emulsion,the petroleum oils, and synthetic oils having been described herein. Themetal working lubricant containing water may also comprise a solid orparticulate inorganic or organic lubricant and water where the solid orparticulate lubricants are as described herein.

[0095] The lubricant compositions of the present invention and thelubricant compositions used according to the method of the invention maycomprise room temperature liquid compositions having SAE viscosities asdescribed herein or may have the consistency of grease as that term andthose consistencies are described herein.

[0096] Throughout the written description and claims, the lubricant isdescribed as a material for decreasing friction between moving surfacesby which it is meant that the material comprises either a compound orcomposition of matter or mixtures of a compound and a composition ofmatter.

[0097] The average particle size of the particulate inorganic lubricantor organic lubricant or the superabsorbent polymer may be anywhere fromabout <0.5 microns to about 300 microns or about 0.001 in. to about 0.3in. and especially from about 0.005 in. to about 0.2 in. Thesuperabsorbent polymer (as well as the lubricant composition) may alsobe in the form of flakes or sheets.

[0098] The lubricant composition can be either a liquid, including aviscous liquid, or gel, or a solid, whether rigid, semi-rigid orflexible at room temperature. Solid lubricant compositions also includea powdered lubricant composition. One of the outstanding features of thelubricant composition is that it can be shaped by any conventionalmolding or extruding process to form discs, sheets, rods, blocks,powders, or filaments, and especially solid lubricant compositions thatcan be formed to the contours of the surface or surfaces that are beinglubricated.

[0099] Additionally, multiple dry films of the same or differentlubricant composition may also be prepared, i.e. laminar structurelubricants where the layers of the laminate are anywhere from about 2 toabout 25 mils thick. These laminates may also have some laminar layersbased only on the superabsorbent polymer, or the lubricant, and thebalance on the lubricant composition. Additionally, the same ordifferent lubricant composition laminar layers may be used.

[0100] The superabsorbent polymer is used in combination with thelubricant in an amount anywhere from about 0.001 wt% to about 99 wt%,and especially from about 0.1 wt% to about 85 wt%, or from about 0.2 wt%to about 75 wt%, based on the combination of lubricant (with or withoutlubricant additives, or other additives) and superabsorbent polymer. Inone experiment, the superabsorbent polymer is combined with about 350times its weight of powdered graphite. Powders having an averageparticle size of about minus 325 mesh are taken up by some of thesuperabsorbent powders.

[0101] The lubricant and additives, when employed, are combined with thesuperabsorbent polymer by swelling the polymer either by itself ordispersed with the lubricant (and additives when employed), either inwater or in a high humidity environment, e.g. 80% R.H.

[0102] Prior to, or after exposing the superabsorbent polymer to wateror humidity, the polymer, in the form of a powder, flakes or granules ismixed with the lubricant in a conventional mixer, such as a HOBART^(TM)mixer until a uniform dispersion is obtained. This process may befacilitated by employing a solvent or dispersant for the lubricant,preferably in some instances, one that will be easily driven off fromthe lubricant composition of the invention, such as a ketone, especiallythe lower alkyl ketones e.g. acetone MEK, MIBK, DIBK, and the like.

[0103] The lubricant then combines with, is entrapped by or is taken upby the superabsorbent polymer that has been swollen with water or inhigh humidity. The lubricant composition is then dried to remove thewater, for example by placing it in a 27-38% R.H. environment, or undervacuum or at elevated temperatures. This removes substantially all ofthe water introduced in the first part of the process.

[0104] The lubricant composition, prior to removal of water as describedherein, or after removal of water is shaped by molding or extruding, andin the case of forming powdered or granular lubricants, is ground tomesh in a conventional grinding mill after the water has been removed.

[0105] Another outstanding feature of the lubricant compositions istheir ability, under pressure to release the lubricant as a film ordrop, or droplets, such as microdroplets and to recapture the releasedlubricant after pressure is released or ceases. The superabsorbentpolymers of the lubricant compositions in this regard were discovered tohave sponge like properties, even though no sponge like characteristics,such as porosity is visible to the naked or unaided eye, when examiningthe lubricant compositions. However, other matrix compositions can beformulated to have porous characteristics that are plainly visible.

[0106] A lubricant composition is made in the foregoing manner employinggraphite, as noted above, or a 2 mol ethoxylate of isostearyl alcohol(AROSURF^(®) 66 E2). Although the latter is used as a surfactant, italso has some lubricating characteristics and is to be considered as alubricant as well for the purpose of the present invention.

[0107] Other solid fillers, adjuvants and diluents can be used incombination with the lubricants employed in the lubricant composition ofthe present invention, including surfactants, liquid extenders, solventsand the like.

[0108] Additional Examples Illustrative of Manufacturing Procedures forControlled-Delivery

[0109] Superabsorbent Polymer-based Lubricant Compositions or Devices

[0110] I.Admixtures of Superabsorbent Polymers and Lubricants orLubricant Formulations: Water-Free Compositions

[0111] This procedure utilizes the microsponging and entrapment ofwater-based formulations (e.g., suspensions, emulsions, mixtures) of oneor more solid (e.g., graphite and/or carbon) and/or liquid (e.g.,petroleum and/or non-petroleum) lubricants, with or without additionallubricant additives by superabsorbent polymers. Lubricant additives canbe chemically active and/or chemically inert and can includedispersants, solvents, detergents, anti-wear agents, extreme pressureagents, oxidation inhibitors, rust and corrosion inhibitors,emulsifiers, demulsifiers, pour-point depressants, surfactants, foaminhibitors, viscosity improvers, and the like. Superabsorbent polymerscan be in powdered, flaked, granular, composites, extruded, or otherforms prior to admixing with the water-based lubricant formulations.

[0112] In this procedure, the hydrated superabsorbent polymerscontaining various concentrations of the lubricant formulations aredried to remove entrapped water by one or more standard techniques(e.g., heat, low humidity, vacuum, chemicals, microwave, lowtemperature, freeze drying, and the like). Percentage loading of theaqueous solid and/or liquid lubricant components with or without anyadditional lubricant additives within a superabsorbent polymer matrixwill be dependent on the type of superabsorbent polymer (e.g., starchgrafted, acrylate, acrylamide, acrylate/acrylamide, and the like), theporosity of the superabsorbent polymer, the total water absorbency ofthe superabsorbent polymer, the speed of water absorbency, and theconcentration and type of solid and/or liquid lubricant(s)/lubricantformulation used in the admixtures.

[0113] II.Admixtures of Superabsorbent Polymers and Lubricants orLubricant Formulations: Water-Based Compositions

[0114] This procedure utilizes the microsponging and entrapment ofwaterformulations (e.g., suspensions, emulsions, mixtures, and the like)of one or more solid and/or liquid lubricants, with or withoutadditional lubricant additives by one or more superabsorbent polymers.Superabsorbent polymers can be powdered, flaked, granular, composites,extruded, or other forms prior to admixing with the water-basedlubricant(s) or lubricant formulations.

[0115] Hydrated superabsorbent polymers containing variousconcentrations of the lubricant formulation are in single units (e.g.,granules) or fused masses (e.g., gels) of hydrogels of variousviscosities, sizes, shapes, tensile strengths, and consistencies. Thehydrogel form and/or viscosity of the superabsorbent polymer-basedlubricant formulation will be dependent on the concentration of water,the concentration and type(s) of superabsorbent polymers, the waterabsorbency of the superabsorbent polymer(s), and the concentration andtype(s) of solid and/or liquid lubricant(s) or lubricant formulationsused in the aqueous admixtures.

[0116] III.Admixtures of Superabsorbent Polymers and Lubricants orLubricant Formulations: Agglomerated Water-Free Compositions

[0117] This procedure consists of admixing one or more superabsorbentpolymers (e.g., powders, flakes, granules) with one or more solid and/orliquid lubricants, with or without additional lubricant additives, andagglomerating the homogeneous or heterogeneous admixture compositions atvarious humidities, pressures, temperatures, and the like, by standardtechniques to form solid unified pellets, extrusions, sheets,composites, pads, fibers, granules, laminates, and the like, in variousshapes, sizes and structural consistencies (e.g., flexible, rigid orhigh/low tensile strength). The type of agglomerated composition will bedependent on the type and concentration of one or more superabsorbentpolymers, the type and concentration of one or more lubricant andlubricant additives, and the agglomeration procedures utilized infabricating the lubricant composition.

[0118] IV.Admixtures of Monomers and Lubricants or LubricantFormulations: Polymerization of Polymer/Lubricant Components

[0119] This procedure consists of polymerizing the monomers utilized inthe manufacturing of the superabsorbent polymers (i.e., with or withoutcrosslinking agents) and one or more solid and/or liquid lubricants andlubricant additives into solid matrices (e.g., granules, flakes,pellets, powders, extrusions, and the like) that have lubricantcomponents structurally integrated throughout the superabsorbent polymernetwork.

[0120] V.Admixtures of Superabsorbent Polymers and Lubricants orLubricant Formulations with Crosslinking Agents

[0121] In this procedure, agglomerated or non-agglomeratedsuperabsorbent polymer-based lubricant compositions are admixed withcrosslinking agents or additional crosslinking agents to impartdifferent binding, release, coating, swelling, or other structural ormatrix characteristics on the solid lubricant compositions.

[0122] Controlled-Delivery Superabsorbent Polymer-Based Lubricant

[0123] Compositions or Devices

[0124] The rate and duration of controlled delivery of one or more solidand/or liquid lubricants from a superabsorbent polymer-based solidmatrix or liquid composition (various viscosities) by diffusion,exuding, deposition, and the like, is proportional to thephysicochemical fluctuations in the superabsorbent polymer due tovariations in temperature, pressure, compressions, abrasion, erosion,friction, biodegradation, humidity, electrical conductance, chemicals,and the like, acting on the lubricant composition utilized to reduce thefriction between two or more moving parts.

[0125] Examples of superabsorbent polymer-based friction-reducingcompositions or devices for use as solid and/or liquid lubricants caninclude the following:

[0126] A.Washers - pressure-sensitive, self-lubricating; flexible,semi-flexible, or rigid, and the like;

[0127] B.Friction reducing plates, pads, composites, agglomerates -self-lubricating, pressure-sensitive, abrasion-sensitive; flexible,semi-flexible, or rigid, and the like;

[0128] C.Bearings - self-lubricating, composites, metal-matrixcomposites, and the like;

[0129] D.Shock absorbers/struts/pressure pads/impact plates -self-lubricating, pressure-sensitive, and the like;

[0130] E.Shims or spacers;

[0131] F.Seals;

[0132] G.Gels or greases - variable-viscosity oil and/or water-basedcompositions.

[0133] Prefabricated superabsorbent polymer-based controlled-deliverydevices such as washers, pads, and the like, can be designed to besensitive to various physicochemical forces such as pressure,temperature, abrasion and/or humidity, and therefore can beself-lubricating under stress. For example, under stress conditions,agglomerated superabsorbent polymer-based liquid lubricant compositionscan exude small concentrations of the lubricant that is incorporated orentrapped in the superabsorbent polymer matrix to desired areas uponcompaction or compression of the device. Upon compression, the device isreversible and can reabsorb excess lubricant fluid that is in immediatecontact with the device, particularly in a closed system. Solidlubricants can be added to this system and delivered simultaneously withthe liquid lubricants.

[0134] Prefabricated superabsorbent polymer-based devices orcompositions containing solid lubricants can deposit the solid lubricanton desired surfaces, when, for example, vertical or horizontal friction(i.e., a sliding action) occurs across one or more planes of the device,and abrasion of the polymer-lubricant complex causes a deposit of thesolid lubricant to be applied to the target surface. The amount of soliddeposit will be directly proportional to the force applied to thesuperabsorbent polymer matrix.

[0135] The superabsorbent polymer alone can also act as aself-lubricating solid or liquid matrix when variations in the amount ofmoisture/humidity/water are applied to the superabsorbent polymer.Superabsorbent polymers become very slippery when activated by water,and will differentially absorb water based on the chemical constituentsutilized in the polymerization process to manufacture the superabsorbentpolymer. This water-activated action can provide an additional releaseand/or lubricating mechanism in certain situations when superabsorbentpolymers are combined with one or more solid and/or liquid lubricants.For example, compaction and high humidity or humidity fluctuations canact on a superabsorbent polymer-based device to provide release of solidand/or liquid lubricants under a variety of use conditions. Also, thepresence of one or more superabsorbent polymers in a solid or liquidlubricating system or device can act as a moisture scavenger to protectcertain parts, and the like, from the affects of water or watermigration.

[0136] ENVIRONMENTS OF USE FOR SUPERABSORBENT POLYMER-BASED LUBRICANTS

[0137] CLOSED SYSTEMS VS. OPEN SYSTEM ENVIRONMENTS

[0138] Superabsorbent polymer-based lubricant compositions are composedof one or more hydrophilic components. Therefore, the optimum controlleddelivery performance would be expected to be observed in closed orsealed systems that are not exposed to ambient conditions. Nevertheless,short-term lubricant performance can be expected in open environmentsystems.

[0139] EXAMPLE 1

[0140] A series of granular superabsorbent polymer-based lubricantcompositions are fabricated using microsponging and entrapmentprocedures. These procedures utilized prefabricated superabsorbentpolymer granules (irregularly shaped) that ranged in size from ca. 1 to3 mm in diameter. Carbon, graphite (ca.-325 mesh), and a combination ofcarbon and graphite are utilized in the compositions as examples ofsolid lubricants. Superabsorbent polymers used as matrices for the solidlubricants are SANWET^(®) IM-1500 LP (starch grafted sodiumpolyacrylate), ARIDALL^(®) 11250 (potassium polyacrylate, lightlycrosslinked) and DOW^(®) XU 40346.00 (partial sodium salt of crosslinkedpolypropenoic acid). PEMULEN^(®)TR-1 (acrylic acid copolymer) is used inone series as a formulation or lubricant additive to enhance the loadingcharacteristics of a superabsorbent polymer granule.

[0141] Solid lubricants are incorporated into the superabsorbent polymergranules in a time and temperature - dependent aqueous microsponging andentrapment protocol. The speed of granule absorption and theconcentration of solid lubricant(s) or lubricant formulation entrappedwithin the superabsorbent polymer matrices are dependent on factors suchas the type of superabsorbent polymer, porosity of the granules, watertemperature, and the type and/or concentration of formulation andlubricant additives utilized in the admixture. Dehydration of thehydrated granules containing the lubricant(s) is accomplished by airdrying at low humidity or by chemical drying in a series of solventbaths.

[0142] The following protocols are utilized to load the 3 types ofsuperabsorbent polymer granules with the solid lubricant(s) or lubricantformulations.

[0143] SANWET^(®) IM-1500 LP(a) -- A formulation of 299.625 g (79.9%w/w) distilled water and 0.375 g (0.1% w/w) PEMULEN^(®) TR-1 is mixed in500 ml NALGENE^(®) bottles on a STROKEMASTER^(®) paint shaker for ca. 30minutes. Then, 75 g (20% w/w) carbon (ca. -325 mesh) is added to theaqueous formulation and mixed on the paint shaker for ca. 5 minutes. Tothis mixture, 5 g (w/w) SANWET^(®) IM-1500 LP superabsorbent polymergranules are added and shaking is continued for an additional 60minutes. The fully swollen SANWET^(®) IM-1500 LP granules containing thecarbon, PEMULEN^(®) TR-1, and water are sieved (30 mesh) and dried toremove the entrapped water for ca. 96 hr in a room maintained at ca.27-38% RH and 23-26 C. Dehydrated granules are stored in plasticbottles. The granular controlled-release lubricant compositionsconsisted of 13.1% (w/w) SANWET^(®) IM-1500 LP + 86.4% (w/w) carbon +0.5% (w/w) PEMULEN^(®) TR-1. SANWET^(®) IM-1500 LP in a relatedexperiment employed in an amount of 5.0087 grams is observed toincrease, on a dry weight basis to 38.1043 grams, i.e., an increase inweight of 660.8% due to absorption of the carbon and PEMULEN^(®) TR-1.

[0144] ARIDALL^(®) 11250(b) -- A formulation of 24 g (80% w/w) distilledwater, 3 g (10% w/w) graphite, and 3 g (10% w/w) carbon is heated to 80C in a 100 ml KIMAX^(®) beaker on a hot plate. To this formulation,0.4062 g ARIDALL^(®) 11250 granules are added to the heated formulationfor ca. 5 to 10 seconds. The beaker is then removed from the hot plateand vigorously swirled for ca. 30 seconds. The fully hydrated granulescontaining the carbon and graphite are then washed in the followingseries of 100 ml serial solvent baths to remove the water: 3 minutes in10% acetone/90% distilled water; 3 minutes in 30% acetone/70% distilledwater; 3 minutes in 50% acetone/50% distilled water; 3 minutes in 70%acetone/30% distilled water; 3 minutes in 90% acetone/10% distilledwater; and 5 minutes in 100% acetone. Granules appeared to be ca. 90%dehydrated at this time. Granules containing the remaining water andsolid lubricants are transferred to a low humidity room (27-38% RH and23-26 C) for 24-48 hr to assure that the granules are totally dry.Dehydrated granules are stored in glass vials. The granularcontrolled-release lubricant compositions consisted of 20.6% (w/w)ARIDALL^(®) 11250 + 39.7% carbon (w/w) and 39.7% (w/w) graphite. The0.4062 grams of ARIDALL^(®) 11250 granules increased in weight to 1.9768grams on a dry weight basis, an increase in weight of 386.7% due toabsorption of graphite and carbon.

[0145] ARIDALL^(®) 11250(c) -- Another formulation of 48 g of distilledwater (80% w/w) and 12 g carbon (20% w/w) is heated to 80 C in a 100 mlKIMAX^(®) beaker on a hot plate. To this formulation, 0.8031 gARIDALL^(®) 11250 granules are added to the heated formulation for ca.5-10 seconds. The beaker is then removed from the hot plate andvigorously swirled to ca. 30 seconds. The fully hydrated granulescontaining the carbon are then washed in the following series of 100 mlsolvent baths to remove the water; 3 minutes in 10% acetone/90%distilled water; 3 minutes in 30% acetone/70% distilled water; 3 minutesin 50% acetone/50% distilled water; 3 minutes in 70% acetone/30%distilled water; 3 minutes in 90% acetone/10% distilled water; and 5minutes in 100% acetone. Granules appeared to be ca. 90% dehydrated atthis time. Granules containing the remaining water and solid lubricantare transferred to a low humidity room (27-38% RH and 23-26 C) for 24-48hr to assure that the granules are totally dry. Dehydrated granules arestored in glass vials. The granular controlled-release lubricantcompositions consisted of 30.8% (w/w) ARIDALL^(®) 11250 + 69.2% (w/w)carbon. The 0.8031 grams of ARIDALL^(®) 11250 granules increased inweight to 2.6101 grams on a dry weight basis, i.e. an increase in weightof 225% due to the absorption of carbon.

[0146] ARIDALL^(®) 11250(d) -- In another formulation, 27 g (90% w/w)distilled water, 1.5 g (5% w/w) carbon and 1.5 g (5% w/w) graphite areheated to 80 C in a 100 ml KIMAX^(®) beaker on a hot plate. To thisformulation, 0.4023 g ARIDALL^(®) 11250 granules are added to the heatedformulation for ca. 5-10 minutes. The beaker is then removed from thehot plate and vigorously swirled for ca. 40 seconds. The fully hydratedgranules containing the carbon and graphite are then washed in aNALGENE^(®) bottle containing 500 ml of 2-propanol for ca. 15 minutes.Granules appeared to be ca. 75% dehydrated at this time. Granulescontaining the remaining water and solid lubricants are transferred to alow humidity room (27-38% RH and 23-26 C) for 24-48 hr to assure thatthe granules are totally dry. Dehydrated granules are stored in glassvials. The granular controlled-release lubricant compositions consistedof 44% (w/w) ARIDALL^(®) 11250 + 28% (w/w) carbon and 28% (w/w)graphite. The 0.4023 grams of ARIDALL^(®) oven 250 increased in weightto 0.9144 grams on a dry weight basis, i.e. an increase in weight of127.3% due to the absorption of carbon and graphite.

[0147] DOW^(®) XU 40346.00(e) -- A formulation 57 g (95% w/w) distilledwater and 3 g (5% w/w) graphite is heated to 80 C in a 100 ml KIMAX^(®)beaker on a hot plate. To this formulation, 0.8022 g DOW^(®) XU 40346.00granules are added to the heated formulation for ca. 4 minutes. Thebeaker is then removed from the hot plate and vigorously swirled for ca.30 seconds. The fully hydrated granules containing the graphite aresieved (30 mesh) and transferred to a low humidity drying room (27-38%RH and 23-26° C) for 48 hr to remove the entrapped water. Dehydratedgranules are stored in glass vials. The granular controlled-releaselubricant compositions consisted of 40.6% (w/w) DOW^(®) XU 40346.00 +59.4% (w/w) graphite. The 0.8022 grams of DOW^(®) XU 40346.00 increasedin weight to 1.9750 grams on a dry weight basis, i.e., an increase of146.2% due to the absorption of graphite.

[0148] EXAMPLE 2

[0149] A series of agglomerated (i.e., granules, briquets or disquets)superabsorbent polymer based lubricant compositions are fabricated usingmixing and compaction procedures. Agglomeration procedures utilizedprefabricated superabsorbent polymer powders that ranged in sizes fromca. 1 to 300 microns in diameter. Non-petroleum oils or surfactants suchas AROSURF^(®) 66-E2(POE(2) isostearyl alcohol; Sherex Chemical Co.,Inc.), petroleum oils such as MARVEL^(®) Mystery Oil (MARVEL OilCompany, Inc.) or ROYCO^(®) 481 Oil (Grade 1010; Royal Lubricants Co.,Inc.) and/or citrate esters (CITROFLEX^(®)/MORFLEX^(®) products) such asCITROFLEX^(®) A-4 (acetyltri-n-butyl citrate; MORFLEX, Inc.) areutilized in the agglomerated compositions as examples of liquidlubricants. It should be noted that in addition to having lubricatingcharacteristics, AROSURF^(®) 66-E2 and CITROFLEX^(®) A-4 are also usedas formulation/lubricant additives (i.e., plasticizers) to providevarious degrees of flexibility or elastomeric characteristics to theagglomerated matrices. Superabsorbent polymers used as matrices for theliquid lubricants are WATER LOCK^(®) A-1OO, A-120, A-140, A-180, andA-200 (starch-g-poly(2-propenamide-co-2-propenoic acid, sodium salt)),SUPERSORB^(®) (starch acrylonitrile copolymer), FAVOR^(®) CA 100(crosslinked potassium polyacrylate/polyacrylamide copolymer),STOCKOSORB^(®) 400F (crosslinked potassium polyacrylate/polyacrylamideterpolymer), and AQUAKEEP^(®) J-500 (acrylic acid, polymers, sodiumsalt).

[0150] Liquid lubricants and formulation/lubricant additives areagglomerated into granules, disquets or briquets in a series of time,moisture, and solvent-dependent admixing and agglomeration procedures.The physicochemical characteristics of the controlled-delivery lubricantcomposition fabricated in the agglomeration process is observed to varywith the type and concentration of superabsorbent polymer(s),solvent(s), lubricant(s), and formulation/lubricant additive(s) utilizedin the admixtures. Additional matrix variations are observed by alteringformulation moisture, the order of component admixing, the degree ofcompaction of the formulation components, and the mixing speed and shearused to blend the formulation components. Vigorous mixing of theformulation components is utilized to effect solvent (e.g., acetoneand/or 2-propanol) evaporation.

[0151] In several admixtures, the powdered formulations are agglomeratedinto granules that ranged in size from ca. 0.5-5 mm in diameter uponevaporation of the solvent(s), while in other admixtures a powderedcomposition remained upon evaporation of the solvent. Solvent-freecompositions are then placed into molds and compacted by hand orsolvent-based compositions are poured into molds before all the solventis driven off and not compacted. Granular and powdered superabsorbentpolymer-based lubricant compositions are cured at high humidity and thendried at low humidity to remove entrapped moisture.

[0152] The following admixing and agglomeration protocols are utilizedto fabricate the superabsorbent polymer-based granules, disquet orbriquet compositions: WATERLOCK^(®) A-140(a) -- A formulation of 25 g(25% w/w) of MARVEL^(®) Mystery Oil or ROYCO^(®) 481 Oil is added to 100g of acetone in a stainless steel bowl and blended with a KITCHENAID^(®)KSM 90 mixer (wire whip attachment; #2 speed) for ca. 5 minutes in aroom maintained at ca. 83% RH and 25°C. While mixing, 75 g (75% w/w) ofWATERLOCK^(®) A-140 superabsorbent polymer powder is added to each ofthe petroleum oil/acetone mixtures. Mixing is continued to drive off theacetone for ca. 1-2 hr. During this mixing period, each of the petroleumoil/WATERLOCK^(®) A-140 superabsorbent polymer compositions agglomeratedinto masses of granules that ranged in size from <1 to 5 mm in diameter.Formation of agglomerated granules is a function of the high humidityduring the mixing process. The agglomerated granules are placed onNALGENE^(®) sieves in a high humidity curing room maintained at ca. 80%RH and 27°C for ca. 24 hr so the agglomerated granules would absorbmoisture to assure that the superabsorbent polymer powder/lubricantcomplex would remain bound into distinct granules. The granularsuperabsorbent polymer-based compositions are then placed into a lowhumidity drying room maintained at ca. 27-38% RH and 25-26°C for ca. 48hr. Dried superabsorbent polymer-based controlled-delivery granulescontaining MARVEL^(®) Mystery Oil or ROYCO^(®) 481 Oil are stored inglass vials.

[0153] Waterlock^(®) A-1OO, A-120, A-140, A-180, and A-200;SUPERSORB^(®), FAVOR^(®) CA 100: STOCKOSORB 400 F: and AQUAKEEP J-500(b)-- A formulation of 100 g (50% w/w) of AROSURF^(®) 66-E2 is added to 300g of acetone in a stainless steel bowl and blended with a KITCHENAID^(®)KSM 90 mixer (wire whip attachment; #2 speed) for ca. 5 minutes in aroom maintained at ca. 27-38% RH and 25-26°C. While mixing, 100 g (50%w/w) of a WATERLOCK^(®), SUPERSORB^(®), FAVOR^(®), STOCKOSORB^(®) orAQUAKEEP^(®) superabsorbent polymer powder are slowly added into theAROSURF^(®) 66-E2/acetone mixture. Mixing is continued until the acetonehad been driven off and the powdered composition is essentially flowable(ca. 2-3 hr). Next, each 1:1 superabsorbent polymer/lubricantcomposition is hand-compacted in a series of plastic petri dishes (35 x10 mm) to form disquets and PEEL-A-WAY^(®) R-30 plastic tissue embeddingmolds (30 mm long x 25 mm wide x 20 mm high) to form briquets. The petridishes and tissue embedding molds containing the compressed powderedlubricant compositions are placed in a high humidity curing roommaintained at ca. 80% RH and 27°C for ca. 72 hr to cause the compactedpowdered formulation to absorb moisture and bind into single unifiedmasses that are generally in the shape of the molds. These compositionsare then placed in a low humidity drying room maintained at ca. 27-38%RH and 25-26°C for ca. 72 hr. Dried briquets and disquets are stored inplastic ZIPLOC^(®) bags. The flexibility, tensile strength, andlubricant characteristics of each agglomerated formulate composition isobserved to vary with the type of superabsorbent polymer that is mixedwith the AROSURF^(®) 66-E2 lubricant.

[0154] WATERLOCK^(®) A-140(c) -- Formulations of 50 g (25% w/w) ofROYCO^(®) 481 Oil or 25 g (25% w/w) of ROYCO^(®) 481 Oil and 25 g (25%w/w) of graphite are added to 200 g or 100 g of acetone in stainlesssteel bowls, respectively, and blended with a KITCHENAID^(®) KSM 90mixer (wire whip attachment; #2 speed) for ca. 5 minutes in a roommaintained at 27-38% RH and 25-26°C. While mixing, 150 g (75% w/w) or 50g (50% w/w) of WATERLOCK^(®) A-140 superabsorbent polymer are slowlyadded into the ROYCO^(®) 481 Oil/Acetone or ROYCO^(®) 481Oil/graphite/acetone mixtures, respectively. After ca. 1 hr of mixing,ca. one-half of each semi-viscous formulation containing a flowableacetone-based formulation is poured into a series of plastic petridishes (35 x 10 mm) to form disquets and PEEL-A-WAY^(®) R-30 plastictissue embedding molds (30 mm long x 25 mm wide x 20 mm high) to formbriquets. The uncompressed compositions in each mold are placed in a lowhumidity drying room maintained at 27-30% RH and 25-26°C for 24 hr toallow the acetone to volatilize from the compositions. The compositionsare then transferred into a high humidity curing room maintained at ca.80% RH and 27°C for 72 hr to assure that the superabsorbentpolymer-based lubricant compositions would absorb moisture and bind intounified masses that are in the shape of the curing molds. Finally, thecompositions are transferred back into the low humidity drying room(27-38% RH and 25-26°C) to remove the entrapped water from the matrices.Dried disquet and briquet formulations are stored in plastic ZIPLOC^(®)bags. Mixing is continued for the other half of the 2 formulations foran additional 1 hour until the acetone had volatilized from each of thepowdered compositions. Each superabsorbent polymer-based lubricantcomposition is then hand-compacted in a series of plastic petri dishes(35 x 10 mm) and PEEL-A-WAY^(®) R-30 plastic tissue embedding molds (30mm long x 25 mm wide and 20 mm high) to form disquets or briquets. Themolds containing each powdered lubricant composition are placed into ahigh humidity curing room maintained at 80% RH and 27°C for 72 hr toallow the compositions to absorb moisture and bind into unified matricesthat are in the shape of their molds. These compositions are then placedinto a low humidity drying room maintained at 27-38% RH and 25-26°C foran additional 72 hr to assure that the entrapped water had been removedfrom the matrices. Agglomerated compositions are stored in plasticZIPLOC^(®) bags. Differences in the flexibility, tensile strength, andlubricant characteristics are observed between uncompacted and compactedagglomerated compositions of the two lubricant formulations.

[0155] WATERLOCK^(®) A-140(d) -- Formulations of 20 g (10% w/w) ofAROSURF^(®) 66-E2 or CITROFLEX^(®) A-4 and 200 g of acetone are blendedin stainless steel bowls with a KITCHENAID^(®) KSM 90 mixer (wire whipattachment; speed #2) for ca. 5 minutes in a room maintained at ca.27-38% RH and 25-26°C. While mixing, 130 g (65% w/w) or 100 g (50% w/w)of WATERLOCK^(®) A-140 superabsorbent polymer is slowly added to theacetone/AROSURF^(®) 66-E2 or CITROFLEX^(®) A-4 blends and mixed for anadditional 5 minutes. At this time, 50 g (25% w/w) of ROYCO^(®) 481 Oilare added to the 130 g polymer/20 g AROSURF^(®) or CITROFLEX^(®)/200 gacetone formulations and mixed for ca. 1 hr. In the other formulations,40 g (20% w/w) of ROYCO^(®) 481 Oil are added to the 100 g polymer/20 gAROSURF^(®) or CITROFLEX^(®)/200 g acetone formulations and mixed for 5minutes. Finally, 40 g (20% w/w) of graphite is added to thesecompositions and mixed for ca. 1 hr. The remaining procedures forformulating the uncompressed and compressed superabsorbent polymer-basedlubricant compositions are as described in the preceding WATERLOCK^(®)A-140(c) protocol.

[0156] WATERLOCK^(®) A-140(e) -- Formulations of 50 g (25% w/w) ofAROSURF^(®) 66-E2 or CITROFLEX^(®) A-4 and 200 g of acetone are blendedin stainless steel bowls with a KITCHENAID^(®) KSM 90 mixer (wire whipattachment; speed #2) for ca. 5 minutes in a room maintained at 27-38%RH and 25-26°C. While mixing, 100 g (50% w/w) of WATERLOCK^(®) A-140superabsorbent polymer are slowly added to the acetone/AROSURF^(®) 66-E2or CITROFLEX^(®) A-4 blends and mixed for an additional 5 minutes. Atthis time, 50 g (25% w/w) of graphite are added to the AROSURF^(®) 66-E2or CITROFLEX^(®) A-4 formulations and mixed for ca. 1 hr. The remainingprocedures for formulating the uncompressed and compressedsuperabsorbent polymer-based lubricant compositions are as described inthe WATERLOCK^(®) A-140(c) protocol.

[0157] WATERLOCK^(®) A-140(f) -- A formulation of 100 g (50% w/w) ofgraphite is added to 200 g of acetone in a stainless steel bowl andblended with a KITCHENAID^(®) KSM 90 mixer (wire whip attachment; #2speed) for ca. 5 minutes in a room maintained at 27RH and 25-26°C. Whilemixing, 100 g (50% w/w) of WATERLOCK^(®) A-140 superabsorbent polymerare slowly added to the acetone/graphite admixture and mixed for ca. 1hour. The remaining procedures for formulating the uncompressed andcompressed superabsorbent polymer-based lubricant compositions are asdescribed in the WATERLOCK^(®) A-140(c) protocol.

[0158] WATERLOCK^(®) A-140(g) -- Formulations of 80 g (40% w/w)AROSURF^(®) 66-E2, 20 g (10% w/w) graphite or ROYCO^(®) 481 Oil or 10 g(5% w/w) of ROYCO^(®) 481 Oil and 10 g (5% w/w) of graphite and 200 g ofacetone are added to stainless steel bowls and blended with aKITCHENAID^(®) KSM 90 mixer (wire whip attachment; #2 speed) for ca. 5minutes in a room maintained at 27-38% RH and 25-26°C. While mixing, 100g (50% w/w) of WATERLOCK^(®) A-140 superabsorbent polymer are slowlyadded to the graphite and/or ROYCO^(®) 481 Oil formulations ofAROSURF^(®) 66-E2 and acetone and mixed for ca. 2 hrs to thoroughlyblend the components while volatilizing the acetone. Each superabsorbentpolymer-based graphite and/or ROYCO^(®) 481 Oil powdered composition isthen hand-compacted in plastic petri dishes (35 x 10 mm) to formdisquets. The plastic petri dish compositions are placed into a highhumidity curing room maintained at 80% RH and 27°C for 72 hr to allowthe superabsorbent polymer in the lubricant admixtures to absorbmoisture and bind into unified matrices that are in the shape of thepetri dishes. Petri dishes containing the graphite and/or ROYCO^(®) 481Oil compositions are then placed into a low humidity drying room (27-38%RH and 25°C) for an additional 72 hr to assure that the entrapped waterhad evaporated from the matrices. When compared to several otherAROSURF^(®)/graphite and/or AROSURF^(®)/ROYCO^(®) 481 Oil disquetcompositions fabricated on the protocols indicated above, it appearedthat the flexibility, tensile strength, and superabsorbent polymer-basedlubricant binding characteristics could be altered by varying theconcentration of AROSURF^(®) 66-E2 in the formulation. Similar findingsare expected with CITROFLEX^(®) formulations.

[0159] STOCKOSORB^(®) 400 F(h) -- A formulation of 50 g (25% w/w)graphite and 50 g (25% w/w) of ROYCO^(®) 481 Oil is added to 200 g ofacetone in a stainless steel bowl and blended with a KITCHENAID^(®) KSM90 mixer (wire whip attachment; #2 speed) for ca. 10 minutes in a roommaintained at 27-38% RH and 25-26°C. While mixing, 100 g (50% w/w) ofSTOCKOSORB^(®) 400F superabsorbent polymer are slowly added to theacetone/graphite/ROYCO^(®) 481 Oil admixture and mixed for ca. 1 hr. Theremaining procedures for formulating the uncompressed and compressedsuperabsorbent polymer-based lubricant compositions are as described inthe WATERLOCK^(®) A-140(c) protocol.

[0160] STOCKOSORB^(®) 400F(i) -- A formulation of 25 g (12.5% w/w)AROSURF^(®) 66-E2 and 200 g of acetone are added to a stainless steelbowl and blended with a KITCHENAID^(®) KSM 90 mixer (wire whipattachment; #2 speed) for ca. 5 minutes in a room maintained at 27-38%RH and 25-26°C. While mixing, 100 g (50% w/w) of STOCKOSORB^(®) 400Fsuperabsorbent polymer are slowly added to the AROSURF^(®) 66-E2/acetoneblend and mixed for an additional 5 minutes. At this time, 25 g (12.5%w/w) ROYCO^(®) 481 Oil are added to the formulation while mixing iscontinued for an additional 5 minutes. Finally, 50 g (25% w/w) ofgraphite are added to the admixture while mixing is continued for ca. 1hr. The remaining procedures for formulating the uncompressed andcompressed superabsorbent polymer based lubricant compositions are asdescribed in the WATERLOCK^(®) A-140(c) protocol.

[0161] EXAMPLE 3

[0162] A series of aqueous semiviscous to viscous superabsorbentpolymer-based lubricant compositions are formulated using admixingprocedures. The procedures utilized several types of superabsorbentpolymer powders or fine granules that ranged in size from ca. <0.5 to300 microns. Liquid lubricants utilized as examples in the formulationsare the petroleum oils MARVEL^(®) Mystery Oil, and/or ROYCO^(®) 481 Oil,the non-petroleum oil AROSURF^(®) 66-E2, and/or water. Graphite (ca.-325 mesh) and/or carbon (ca. -325 mesh) are utilized as examples ofsolid lubricants in the aqueous superabsorbent polymer formulations orcombined with one or more petroleum and/or non-petroleum liquidlubricants to form aqueous multicomponent lubricant formulations.Formulation or lubricant additives such as polymer or non-polymeremulsifiers, dispersants, plasticizers, surfactants, suspending agents,viscosity modifying agents, and the like, could be optionally added tothe aqueous compositions to enhance the overall characteristics of oneor more solid and/or liquid lubricants. Superabsorbent polymers used asmatrices in the liquid compositions are FAVOR^(®) CA 100 (crosslinkedpotassium polyacrylate/polyacrylamide copolymer), STOCKOSORB^(®) 400F(crosslinked potassium polyacrylate/polyacrylamide terpolymer),SANWET^(®) IM-1500F (starch grafted sodium polyacrylate), ARIDALL^(®)1125F (potassium polyacrylate, lightly crosslinked), DOW^(®) XU 40346.00(partial sodium salt of crosslinked polypropenoic acid), WATERLOCK^(®)A-180 (starch-g-poly(2-propenamide-co-2-propenoic acid, sodium salt),WATERLOCK^(®) B-204 (starch-g-poly(2-propenamide-co-2-propenoic acid,potassium salt), AQUASORB^(®)/AQUASTORE^(®) F (copolymer of acrylamideand sodium acrylate), SUPERSORB^(®) (starch acrylonitrile copolymer),ALCOSORB^(®) AB3F (crosslinked polyacrylamide copolymer), andAQUAKEEP^(®) J-550 (acrylic acid, polymers, sodium salt). A commercialformulation of acrylamide-acrylic acid sodium salt copolymer emulsion inhydrocarbon oil (AQUASORB^(®) EM-533; SNF Floeger, France) is also usedas a superabsorbent polymer-based liquid lubricant.

[0163] Water-based liquid and/or solid lubricants are vigorously mixedwith one or more superabsorbent polymers to form a variety ofvariable-viscosity gels, semi-gels, creams or grease-like compositionswhose physicochemical characteristics are dependent on the type andconcentration of superabsorbent polymer(s), the type and concentrationof lubricant(s), the water quality and concentration of water utilizedto activate the swelling/gelling of the superabsorbent polymer(s), thetype and concentration of formulation/lubricant additives, the order ofcomponent mixing, and the shear strength utilized to mix the components.Optimal performance of these water-based superabsorbentpolymer-lubricant compositions would be expected in a closed or sealedsystem. This would allow the variable-viscosity composition to retainthe original swelling capacity or hydrogel consistency of thesuperabsorbent polymer(s) due to little or no evaporation of water thatis bound within the superabsorbent polymer matrix, and therefore,maintain consistent lubricating characteristics. However, when used inan open system, evaporation of the water from the aqueous superabsorbentpolymer-based lubricant compositions would cause the superabsorbentpolymer to shrink and lose its hydrogel and viscosity characteristics,thereby requiring the addition of water to reform the composition to aconsistency that is similar to that observed in the originalcomposition.

[0164] In other formulations, liquid and/or solid lubricants could beadmixed with the superabsorbent polymer(s) into an initial nonaqueouscomposition. Various concentrations of water could be added to theseformulations in a final step to activate the lubricant composition toform gels, semi-gels, creams, and the like, of various viscosities inthe environment of use (e.g., in a closed system via a fitting).

[0165] The following admixing protocols are utilized to formulate thevariable-viscosity superabsorbent polymer-based lubricant compositions.

[0166] FAVOR^(®)CA 100, STOCKOSORB^(®) 400F, SANWET^(®) IM-1500F,ARIDALL^(®) 1125F, DOW^(®) XU 40346.00, WATERLOCK^(®) A-180,WATERLOCK^(®) B-204, AQUASORB^(®)/AQUASTORE^(®)F, SUPERSORB^(®),ALCOSORB^(®) AB3F, and AQUAKEEP^(®) J-550(a)) -- Formulations of 49.95 g(99.9% w/w), 49.9 g (99.8% w/w), 49.875 g (99.75%), 49.85 g (99.7% w/w),49.8 g (99.6% w/w), 49.775 g (99.55% w/w), or 99.65 g (99.3% w/w) ofdistilled water (i.e., acting as lubricant) and 0.1 g (0.2% w/w), 0.125g (0.25% w/w), 0.15 g (0.3% w/w), 0.2 g (0.4% w/w), 0.225 g (0.45% w/w),0.25 g (0.5% w/w), or 0.35 g (0.7% w/w) of each of the superabsorbentpolymers are vigorously hand-shaken in 60 ml glass prescription bottles.The bottles are then thoroughly mixed on a STROKEMASTER^(®) paint shakerfor ca. 5 minutes to form a variety of slightly viscous to highlyviscous hydrogel lubricant formulations. Formulation characteristics(e.g., viscosity and pourability) are observed to vary with the type andconcentration of superabsorbent polymer utilized in the distilled waterformulations.

[0167] FAVOR^(®)CA 100, STOCKOSORB^(®) 400F, SANWET^(®) IM-1500F,ARIDALL^(®) 1125F, DOW^(®) XU 40346.00, WATERLOCK^(®) A-180,WATERLOCK^(®) B-204, AQUASORB^(®)/AQUASTORE^(®)F, SUPERSORB^(®),ALCOSORB^(®) ABF, and AQUAKEEP^(®) J-550(b)) -- Formulations of 3 g (10%w/w) graphite or carbon, or 1.5 g (5% w/w) of graphite and 1.5 g (5%w/w) of carbon and 26.94 g (89.8% w/w) or 26.91 g (89.7%) of distilledwater are admixed with a spatula in hinged-lid polyethylene containers(35 x 45 mm diameter; 50 mil capacity) for ca. one minute. Then 0.06 g(0.2% w/w) or 0.09 g (0.3% w/w) of each superabsorbent polymer is addedto each graphite, carbon, or carbon/graphite formulation and mixed witha spatula for ca. 2 minutes. PARAFILM^(®) M is placed over thecontainers before the snap-lid is closed and the containers containingthe 0.2% or 0.3% superabsorbent polymers in the lubricant formulationare mixed on a STROKEMASTER^(®) paint shaker for 10 minutes or 15minutes, respectively. Containers of the variable-viscosity lubricantcompositions are stored in ZIPLOC^(®) bags. Formulation characteristics(e.g., viscosity) are observed to vary with the type and/orconcentration of lubricant(s) utilized in the compositions.

[0168] FAVOR^(®)CA 100, STOCKOSORB^(®) 400F, SANWET^(®) IM-1500F,ARIDALL^(®) 1125F, DOW^(®) XU 40346.00, WATERLOCK^(®) A-180,WATERLOCK^(®) B-204, AQUASORB^(®)/AQUASTORE^(®)F, SUPERSORB^(®),ALCOSORB^(®) AB3F, and AQUAKEEP^(®) J-550 (c) -- Formulations of 1.5 g(5% w/w) of ROYCO^(®) 481 Oil and 28.47 g (94.9% w/w), 28.41 g (94.7%w/w), 28.35 g (94.5% w/w), 28.29 (94.3% w/w), and 28.20 g (94% w/w)distilled water are added to hinged-lid polyethylene containers (35 x 45mm diameter; 50 ml capacity) and mixed on a STROKEMASTER^(®) paintshaker for ca. 10 minutes. Then, 0.03 g (0.1% w/w), 0.09 g (0.3% w/w),0.15 g (0.5% w/w), 0.21 g (0.7% w/w), and 0.3 g (1% w/w) of eachsuperabsorbent polymer is added to each respective container andvigorously hand-shaken for ca. 1-2 minutes. To assure thorough mixing,the containers with the 0.1%, 0.3%, 0.5%, 0.7% and 1% superabsorbentpolymer-based lubricant compositions are placed on the paint shaker forca, 5, 10, 15, 20, and 25 minutes, respectively. PARAFILM^(®) M isplaced over the containers before the snaplids are closed to assure thatthe lids are tightly sealed before mixing on the paint shaker.Containers of the variable-viscosity lubricant compositions are storedin ZIPLOC^(®) bags. Formulation characteristics (e.g., viscosity) areobserved to vary with the type and/or concentration of superabsorbentpolymer and type and/or concentration of lubricant utilized in thecompositions.

[0169] FAVOR^(®)CA 100, STOCKOSORB^(®) 400F, SANWET^(®) IM-1500F,ARIDALL^(®) 1125F, DOW^(®) XU 40346.00, WATERLOCK^(®) A-180,WATERLOCK^(®) B-204, AQUASORB^(®)/AQUASTORE^(®)F, SUPERSORB^(®),ALCOSORB^(®) AB3F, and AQUAKEEP^(®) J-550 (d)) -- Formulations of 1.5 g(5% w/w) of ROYCO^(®) 481 Oil and 1.5 g (5% w/w) of graphite or carbonand 0.75 g (2.5% w/w) of graphite and 0.75 g (2.5% ww) of carbon and26.97 g (89.9% w/w), 26.91 g (89.7% w/w), 26.85 g (89.5% w/w), 26.79 g(89.3% w/w), or 26.7% (89% w/w) distilled water are added to hinged-lidpolyethylene containers (35 x 45 mm diameter; 50 ml capacity) and mixedon a STROKEMASTER^(®) paint shaker for ca. 10 minutes. Then 0.03 g (0.1%w/w), 0.09 g (0.3% w/w), 0.15 g (0.5% w/w), 0.21 g (0.7% w/w) and 0.3 g(1% w/w) of each superabsorbent polymer is added to each respectivecontainer and vigorously hand-shaken for ca. 1-2 minutes. To assurethorough mixing, the containers with the 0.1%, 0.3%, 0.5% 0.7%, and 1%superabsorbent polymer-based lubricant compositions are placed on thepaint shaker for ca. 5, 10, 15, 20 and 25 minutes, respectively.PARAFILM^(®) M is placed over the containers before the snap-lids areclosed to assure that the lids are tightly sealed before mixing on thepaint shaker. Containers of the variable-viscosity lubricantcompositions are stored in ZIPLOC^(®) bags. Formulation characteristics(e.g., viscosity) are observed to vary with the type and/orconcentration of superabsorbent polymer and the type and/orconcentration of lubricant(s) utilized in the compositions.

[0170] AQUASORB^(®) EM-533R -- Formulations of 0.9 g (3% w/w), 1.5 g (5%w/w), 2.1 g (7% w/w) or 3 g (10% w/w) of a superabsorbentpolymer/hydrocarbon oil/surfactant blend as supplied by the manufacturerare added to 29.1 g (97% w/w), 28.5 g (95% w/w), 27.9 g (93% w/w) or 27g (90% w/w) of distilled water, respectively, in snap-lid polyethylenecontainers (35 x 45 mm diameter; 50 ml capacity) and vigorously shakenby hand for ca. one minute. PARAFILM^(®) M or aluminum foil is placedover the containers before the snap-lids are sealed to assure that thecontainers would not leak before placing them on STROKEMASTER^(®) paintshaker for ca. 10 minutes to be thoroughly mixed. The variable-viscositylubricant compositions are stored in ZIPLOC^(®) bags. Formulationcharacteristics (e.g., viscosity) varied with the concentration ofAQUASORB^(®) EM-533R in each composition.

[0171] It should be noted that the addition of formulation additivessuch as hydrophilic polymers (e.g., PEMULEN^(®) TR-1/TR-2), silicas(e.g., WESSLON^(®) 50, SUPERNAT^(®) 22), and the like, are shown toimprove the component compatibility in several of the admixturesindicated in this example as well as some of the other examples. Theaffect of silicas on the friction reducing and wear properties of thelubricant composition would, however, have to be evaluated in eachapplication to determine its acceptability in the formulation.

[0172] EXAMPLE 4

[0173] The comparative friction-reducing efficacy of several solid(i.e., granules or disquets) and superabsorbent polymer-based lubricantcompositions indicated in Examples 1-2 is evaluated in a series oflaboratory tests using a lubricant testing device and methods that aremodified from ASTM test standards such as B461 and B526. ASM Handbook,Vol. 18, Friction, Lubrication, and Wear Technology, ASM International,1992, 942 pp.). Non-superabsorbent polymer compositions composed of oneor more lubricants and any lubricant additives are utilized asstandards. A control consisted of a test with no superabsorbent polymeror lubricant(s), i.e., metal to metal.

[0174] In general, a 30 x 18 x 24 inch device consisted of a 7 ½ inchsteel tension arm or bar containing a 2 1/4 inch diameter aluminumimpact/pressure plate or disc that, when lowered, contacted the solidlubricant composition (e.g., disquet) that is placed flat on a 2 3/4inch aluminum cup-like sample-holding plate that is attached to the endof the shaft of a motor (Dayton model 6K255C, 3/4 HP, 3450 RPM, 115Volts, 10.8 AMPS, 60 HZ, 1 Phase, 5/8 inch diameter shaft; DaytonElectric Manufacturing Company, Chicago, Illinois). A 21 inch torquewrench (TEC 250, Snap-On Tools Corporation, Kenosha, Wisconsin) isattached by a bolt to the 7 1/2 inch tension bar to measure thefoot-pounds (ft-lbs) of force applied by hand to a superabsorbentpolymer-based lubricant composition. The maximum foot-pounds that couldbe hand-applied to a superabsorbent polymer-based lubricant compositionis ca. 271 ft-lbs (i.e., a 200 ft-lb reading on the torque wrench isequivalent to a calculated value of 271 ft-lbs based on the length ofthe tension bar and torque wrench).

[0175] Short, intermittent, and extended-term stress tests (Table 1) areconducted in an open system to determine the comparative effectivenessof selected superabsorbent polymer-based lubricant compositions inpreventing or reducing the adverse effects of friction generated at hightorque and high RPM (e.g., high temperature and shear at 271 ft-lbs offorce at 3450 RPM) for various time periods or intervals. The observedeffects of the stresses applied to a solid lubricant composition ormatrix by the testing device are recorded for each test series (e.g.,brittleness, elasticity, temperature effects, controlled releasepotential). The tests are designed to evaluate the controlled releasecharacteristics and effectiveness of the solid superabsorbentpolymer-based lubricant compositions as well as the tensile strength andintegrity of the superabsorbent polymer-based matrices following variousperiods and levels of friction-generated compression-decompression andshear.

[0176] One series of short-term tests is conducted to determine if 271ft-lbs of force applied with the tension bar pressure disk or plate toselected solid controlled delivery superabsorbent polymer-basedlubricant compositions that are placed in a sample-holding cup that isspinning at 3450 RPM would release or deposit enough lubricant from thecompressed matrix to prevent the motor shaft/sample cup from spinning.The duration of each test is ca. 5 seconds. Several solid superabsorbentpolymer-based compositions (e.g., disquets) that reached 271 ft-lbswithout shredding or cracking are re-tested at 271 ft-lbs in aconsecutive series of 5 second start-stop intermittent-term tests up toa maximum of 15 times to determine if a sufficient amount oflubricant(s) would be released or sheared from a unified superabsorbentpolymer-based matrix that is subjected to brief periods of repeatedsevere stresses from high compression, friction, and decompression. Atest is terminated if the motor is stopped before reaching 271 ftand thenumber of effective 271 ft-lb lubricating periods is recorded. It shouldbe noted that the sample cup and pressure plate are cleaned between eachsub-test in a test series. A third series of extended-term stress testsare also conducted at ca. 271 or 135 ft-lbs of force (i.e., a 100 ft-lbreading on the torque wrench is equivalent to a calculated value of 136ft-lbs based on the length of the tension bar and torque wrench). Inthis series, 136 or 271 ft-lbs of force at 3450 RPM is continuallyapplied to several agglomerated superabsorbent polymer-based lubricantcompositions (e.g., disquets or granules) for a 15-minute period todetermine the lubricating efficacy and structural integrity of the solidcompositions. Tests are terminated at 15 minutes or if the motor isstopped before the 15 minute test period is completed, and the durationof effectiveness and condition of the matrix are recorded.

[0177] Tests are conducted in a room maintained at ca. 68-79% RH and21-23°C. Superabsorbent polymer-based lubricant compositions are storedin this room in double-bagged zip-lock pouches prior to testing.

[0178] In general, laboratory test results (Table 1) indicated thatsuperabsorbent polymers could be formulated with one or moreconventional solid and/or liquid lubricants and agglomerated into solidmatrices such as disquets to provide prolonged lubrication under highstress conditions. Fabrication procedures e.g. mixing and agglomerationare shown to be critical to the controlled release characteristics ofthe superabsorbent polymer matrices and to prolonged lubricationperformance. The type, number, and concentration of superabsorbentpolymers, lubricants, lubricant additives, and the order of componentmixing and compression strength directly affect the controlled releasecharacteristics of formulated superabsorbent polymer matrices.

[0179] EXAMPLE 5

[0180] The comparative friction-reducing efficacy of severalvariable-viscosity superabsorbent polymer water-based lubricantcompositions indicated in Example 3 is evaluated in a series oflaboratory tests using a lubricant testing device and methods that aremodified from an ASTM test standard such as D2714 (ASTM Handbook, Vol.18, Friction, Lubrication, and Wear Technology, ASTM International,1992, 942 pp.). Non-superabsorbent polymer compositions composed of oneor more lubricants and any lubricant additives are utilized asstandards. A control consisted of a test with no superabsorbent polymeror lubricant(s), i.e., metal to metal.

[0181] In general, a 24 x 30 x 18 inch device consisting of a 7 1/2 inchsteel tension arm or bar containing a 1 inch wide x 1/2 inch deepimpact/pressure semicircular notch in the based of the bar that, whenlowered, contacted a 1 inch sample-holding collar surrounding a 5/8 inchdiameter shaft of a motor (Dayton model 6K255C, 3/4 HP, 3450 RPM, 115volts, 10.8 AMPS, 60 HZ, 1 Phase, 5/8 inch diameter shaft; DaytonElectric Manufacturing Company, Chicago, Illinois). A 21 inch torquewrench (TEC 250, SnapTools Corporation, Kenosha, Wisconsin) is attachedby a bolt to the 7 1/2 inch tension bar to measure the foot-pounds(ft-lbs) of force applied by hand to a superabsorbent polymer-basedlubricant composition. The maximum foot-pounds that could be handapplied to a superabsorbent polymer-based lubricant composition is 271ft-lbs (i.e., a 200 ft-lb reading on the torque wrench is equivalent toa calculated value of 271 ft-lbs band on the length of the tension barand torque wrench).

[0182] A series of short-term stress tests (Table 2) are conducted in anopen system to determine the comparative effectiveness of selectedsuperabsorbent polymer water-based lubricant compositions in preventingor reducing the adverse effects of friction generated at high torque andhigh RPM (e.g., the lubrication efficacy at 271 ft-lbs of force at 3450RPM). The tests are designed to evaluate the efficacy of thevariable-viscosity water-based superabsorbent polymer lubricantcompositions following a brief period of high compression (i.e., 271ft-lbs) and high friction (i.e., at 3450 RPM).

[0183] The tests are conducted to determine if 271 ft-lbs of force couldbe applied to 0.15 g water-based superabsorbent polymer lubricantcompositions placed on the motor shaft collar that is activated to spinat 3450 RPM, without stopping the motor. The duration of each test isca. 5 seconds. A test with a formulation is terminated if the motor isstopped before reaching 271 ft-lbs, and the ft-lbs achieved is recorded.

[0184] Tests are conducted in a room maintained at ca. 68-79% RH and21-23°C. Water-based superabsorbent polymer lubricant compositions arestored in this room in double-bagged zip-lock pouches prior to testing.

[0185] In general, laboratory test results (Table 2) indicated thatsuperabsorbent polymers could be formulated with water and one or morelubricants into a variety of variable-viscosity hydrogel compositionsthat would effectively lubricate the open test system in short-termevaluations. Tests with standards such as ROYCO^(®) 482 Oil, MARVEL^(®)Mystery Oil, carbon and graphite, graphite, carbon, water, and carbon,graphite, and water stopped the motor before reaching 271 ft-lbs oftorque (i.e., 81-231 ft-lbs). A metal to metal control is observed tostop the motor at 34 ft-lbs of torque.--

[0186] It will be apparent to those skilled in the art that variousmodifications and variations can be made to the lubricant composition ofthe present invention comprising a superabsorbent polymer in combinationwith a material for decreasing friction between moving surfaces as wellas the method for lubricating a surface employing such a compositionwithout departing from the spirit or scope of the invention. It isintended that these modifications and variations of this invention areto be included as part of the invention, provided they come within thescope of the appended claims and their equivalents.

[0187] TABLE 1 Amendment Evaluation of Agglomerated SuperabsorbentPolymer-Base Solid Lubricant Compositions: Short, Intermittent, andExtended-Term Stress Tests Composition Maximum appearance; Compositiontorque (ft- structural type; size lbs) applied integrity (diameter × tocompo- Stopped satisfactory Composition thickness); sition at motor(+)/unsatis- formulation weight (g) 3450 RPM (Yes, No) factory (−)*Short-Term Tests Water- Disquet; 271 No Matrix Lock ® A- 35 × 10 mm;Flat; + 140 (65% w/ 9.04 w) + Citroflex A-4 (10% w/ w) + Royco ® 481 Oil(25% w/w) Water- Disquet; 271 No Matrix Lock ® A- 35 × 9 mm; Flat: + 140(65% w/ 9.04 w) + Aro- surf ® 66-E2 (10% w/ w) + Royco ® 481 Oil (25%w/w) Water- Disquet; 271 No Matrix Lock ® A- 34 × 10 mm; Flat; + 140(50% w/ 8.91 w) + Graph- ite (25% w/ w) + Royco ® 481 Oil (25% w/w)Water- Disquet; 271 No Matrix Lock ® A- 34 × 9 mm; Flat; + 140 (50% w/9.12 w) + Graph- ite (5% w/ w) + Aro- surf ® 66-E2 (40% w/ w) + Royco ®481 Oil (5% w/ w) Water- Disquet; 271 No Matrix Lock ® A- 35 × 9 mm;Flat; + 140 (50% w/ 8.97 w) + Aro- surf ® 66-E2 (40% w/ w) + Roy- co ®481 Oil (10% w/w) Water- Disquet; 271 No Matrix Lock ® A- 35 × 9 mm;Flat; + 140 (50% w/ 9.04 w) + Aro- surf ® 66-E2 (40% w/ w) + Graph- ite(10% w/w) Water- Disquet; 271 No Matrix Lock ® A- 35 × 9 mm; Flat; + 140(50% w/ 9.15 w) + Graph- ite (20% w/ w) + Aro- surf ® 66-E2 (10% w/ w) +Roy- co ® 481 Oil (20% w/w)

[0188] TABLE 1 Amendment Evaluation of Agglomerated SuperabsorbentPolymer-Base Solid Lubricant Composition: Short, Intermittent, andExtended-Term Stress Tests Composition Maximum appearance; Compositiontorque (ft- structural type; size lbs) applied integrity (diameter × tocompo- Stopped satisfactory Composition thickness); sition at motor(+)/unsatis- formulation weight (g) 3450 RPM (Yes, No) factory (−)*Short-Term Tests (cont.) Water- Disquet; 271 No Matrix Lock ® A- 35 × 10mm; Flat; + 140 (50% w/ 9.12 w) + Citro- flex ® A-4 (10% w/w) + Graphite(20% w/w) + Roy- co ® 481 Oil (20% w/w) Water- Disquet; 271 No MatrixLock ® A-100 32 × 8 mm; Flat; + (50% w/w) + 5.89 Arosurf ® 66-E2 (50% w/w) Water- Disquet; 271 No Matrix Lock ® A-120 32 × 8 mm; Flat; + (50%w/w) + 5.88 Arosurf ® 66-E2 (50% w/ w) Water- Granules; 271 No MatricesLock ® A- 6.6 × 6.9 Flat; + 140 (75% w/ mm; 9.13 w) + Roy- co ® 481 Oil(25% w/w) Water- Gran- 271 No Matrices Lock ® A- ules; 2.5 × Flat; + 140(50% w/ 2.8 mm; w) + Marvel ® 9.06 Mystery Oil (50% w/w)Intermittent-Term Tests Water- Disquet; 271 No Matrix Lock ® A- 33 × 8mm; Flat; + 140 (50% w/ 9.12 w) + Aro- surf ® 66- E2 (40% w/ w) + Graph-ite (50% w/ w) + Roy- co ® 481 Oil (5% w/w) Water- Disquet; 271 NoMatrix Lock ® A- 35 × 10 mm; Flat; + 140 (50% w/ 9.12 w) + Aro- surf ®66- E2 (10% w/ w) + Royco ® 481 Oil (25% w/w) Water- Disquet; 271 NoMatrix Lock ® A- 35 × 10 mm; Flat; + 140 (65% w/ 9.04 w) + Aro- surf ®66- E2 (10% w/ w) + Roy- co ® 481 Oil (25% w/w)

[0189] TABLE 1 Amendment Evaluation of Agglomerated SuperabsorbentPolymer-Base Solid Lubricant Compositions: Short, Intermittent, andExtended-Term Stress Tests Composition Maximum appearance; Compositiontorque (ft- structural type; size lbs) applied integrity (diameter × tocompo- Stopped statisfactory Composition thickness); sition at motor(+)/unsatis- formulation weight (g) 3450 RPM (Yes, No) factory (−)*Intermittent-Term Tests (cont.) Water- Disquet; 271 No Matrix Lock ® A-35 × 9 mm; Flat; + 140 (50% w/ 8.91 w) + Graph- ite (25% w/ w) + Aro-surf ® 66- E2 (25% w/w) Water- Disquet; 271 No Matrix Lock ® A- 35 × 9mm; Flat; + 140 (65% w/ 9.08 w) + Citro- flex ® A- 4 (10% w/w) + Royco ®481 Oil (25% w/w) Water- Disquet; 271 No Matrix Lock ® A- 35 × 10 mm;Flat; + 140 (50% w/ 8.94 w) + Graph- ite (25% w/ w) + Roy- co ® 481 Oil(25% w/w) Water- Disquet; 271 No Matrix Lock ® A- 32 × 8 mm; Flat; + 100(50% w/ 5.89 w) + Aro- surf ® 66- E2 (50% w/w) Water- Disquet; 271 NoMatrix Lock ® A- 32 × 8 mm; Flat; + 120 (50% w/ 5.88 w) + Aro- surf ®66- E2 (50% w/w) Extended-Term Tests Water- Disquet; 136 No MatrixLock ® A- 35 × 8 mm; Flat; + 140 (65% w/ 9.07 w) + Citro- flex ® A- 4(10% w/w) + Royco ® 481 Oil (25% w/w) Water- Disquet; 136 No MatrixLock ® A- 35 × 8 mm; Flat; + 140 (65% w/ 9.18 w) + Aro- surf ® 66- E2(10% w/ w) + Roy- co ® 481 Oil (25% w/w) Water- Disquet; 136 No MatrixLock ® A- 35 × 10 mm; Flat; + 140 (50% w/ 8.99 w) + Graph- ite (25% w/w) + Roy- co ® 481 Oil (25% w/w)

[0190] TABLE 1 Amendment Evaluation of Agglomerated SuperabsorbentPolymer-Base Solid Lubricant Compositions: Short, Intermittent, andExtended-Term Stress Tests Composition Maximum appearance Compositiontorque (ft- structural type; size lbs) applied integrity (diameter × tocompo- Stopped satisfactory Composition thickness) sition at motor(+)/unsatis- formulation weight (g) 3450 RPM (Yes, No) factory (−)*Water- Disquet; 136 No Matrix Lock ® A- 35 × 10 mm; Flat; + 140 (50% w/8.82 w) + Aro- surf ® 66- E2 (10% w/ w) + Graph- ite ® (20% w/w) +Royco ® 481 Oil (20% w/w) Water- Disquet; 136 No Matrix Lock ® A- 34 ×10 mm; Flat; + 140 (50% w/ 9.01 w) + Citro- flex ® A-4 (10% w/w) +Graphite A- 4 (20% w/w) + Royco ® 481 Oil (20% w/w) Water- Disquet; 136No Matrix Lock ® A- 35 × 9 mm; Flat; + 140 (50% w/ 9.16 w) + Graph- ite(25% w/ w) + Aro- surf ® 66- E2 (25% w/w) Water- Disquet; 136 No MatrixLock ® A- 33 × 8 mm; Flat; + 120 (50% w/ 5.99 w) + Aro- surf ® 66- E2(50% w/w) Water- Disquet; 136 No Matrix Lock ® A- 32 × 8 mm; Flat; + 100(50% w/ 5.89 w) + Aro- surf ® 66- E2 (50% w/w) Water- Disquet; 271 NoMatrix Lock ® A- 35 × 8 mm; Flat; + 140 (50% w/ 6.03 w) + Aro- surf ®66- E2 (50% w/w) # compositions or standards (e.g., 10% w/w Royco ® 481Oil + 80% w/w Arosurf ® 66-E2 + 10% Graphite applied at 4.5 g) showedonly short-term efficacy that was comparable to the superabsorbentpolymer-base lubricant compositions. However, no effectiveness wasobserved with any nonsuperabsorbent polymer composition in intermittentor extended-term tests (i.e., the motor was rapidly stopped). A nosample metal to metal control was observed to stop the # motor at 27ft-lbs of torque.

[0191] TABLE 2 Evaluation of Variable-Viscosity Water-BaseSuperabsorbent Polymer-Base Solid Lubricant Compositions: Short-TermTests Maximum torque (ft-lbs) Stopped Composition Viscositycharacteristics; applied to compositions at motor formulation weight (g)3450 RPM (Yes, No)* Water (89.7% w/w) + Viscous; 0.15 271 No Carbon (5%w/w) + Graphite (5% w/w) + Alcosorb ® AB3F (0.3% w/w) Water (89.8%w/w) + Viscous; 0.15 271 No Carbon (5% w/w) + Graphite (5% w/w) +Favor ® CA 100 (0.2% w/w) Water (89.8% w/w) + Viscous; 0.15 271 NoCarbon (5% w/w) + Graphite (5% w/w + Sanwet ® IM-1500F (0.2% W/W) Water(89.7% w/w) + Carbon Semiviscous; 0.15 271 No (10% w/w) + Aridall ®1125F (0.3% w/w) Water (89.7% w/w) + Carbon Viscous; 0.15 271 No (10%w/w) + Aquasorb ®/ Aquastore ® F (0.3% w/w) Water (89.7% w/w) + CarbonViscous; 0.15 271 No (10% w/w) + Sanwet ® IM- 1500F (0.3% w/w) Water(89.7% w/w) + Carbon Semiviscous; 0.15 271 No (10% w/w) + SuperSorb ™(0.3%)

[0192] TABLE 2 Evaluation of Variable-Viscosity Water-BaseSuperabsorbent Polymer-Base Solid Lubricant Compositions: Short-TermTests Maximum torque (ft-lbs) Stopped Composition Viscositycharacteristics; applied to compositions at motor formulation weight (g)3450 RPM (Yes, No)* Water (89.7% w/w) + Graphite Semiviscous; 0.15 271No (10% w/w) + DOW XU 40346.00 (0.3% w/w) Water (89.7% w/w) + GraphiteSemiviscous; 0.15 271 No (10% w/w) + Stockosorb ® 400F (0.3% w/w) Water(89.7% w/w) + Graphite Highly Viscous; 0.15 271 No (10% w/w) +Alcosorb ® AB3F (0.3% w/w) Water (89.7% w/w) + Graphite Highly Viscous;0.15 271 No (10% w/w) + Favor ® CA 100 (0.3% w/w) Water (89.7% w/w) +Graphite Semiviscous; 0.15 271 No (10% w/w) + WaterLock ® A-180 (0.3%w/w)

[0193]

Claims
 1. A process for manufacturing a lubricant composition consistingessentially of combining a superabsorbent polymer with a material fordecreasing friction between moving surfaces wherein said superabsorbentpolymer absorbs more than about 100 times its weight in water, and saidmaterial for decreasing friction is a petroleum oil lubricant or greasethereof, a solid inorganic compound, a solid organic compound, watercontaining a lubricant additive, a phosphate, a fatty oil, fatty acid orwax, a synthetic oil lubricant, or grease thereof, or a soap, andmixtures thereof.
 2. A lubricant composition of matter consistingessentially of a product produced by the process of combining asuperabsorbent polymer that absorbs more than about 100 times its weightin water with a material for decreasing friction between movingsurfaces, wherein said material for decreasing friction is a petroleumoil lubricant or grease thereof, a solid inorganic compound, a solidorganic compound, water containing a lubricant additive, a phosphate, afatty oil, fatty acid or wax, a synthetic oil lubricant, or greasethereof, or a soap, and mixtures thereof.
 3. The lubricant compositionof claim 2 consisting essentially of a product produced by the processof combining a superabsorbent polymer with a material for decreasingfriction between moving surfaces, wherein said superabsorbent polymerabsorbs greater than about 100 times its weight in water and is apolymer of acrylic acid, an acrylic ester, acrylonitrile, acrylamide,co-polymers thereof or mixtures thereof, wherein said material fordecreasing friction is a petroleum oil lubricant or grease thereof, andwherein said material for decreasing friction optionally contains alubricant additive, wherein said lubricant additive is an antioxidant,rust inhibitor, antiwear compound, extreme pressure additive, detergent,dispersant, pour point depressant, viscosity-index improver, or foaminhibitor.
 4. The lubricant composition of claim 2 consistingessentially of a product produced by the process of combining asuperabsorbent polymer with a material for decreasing friction betweenmoving surfaces, wherein said superabsorbent polymer absorbs greaterthan about 100 times its weight in water and is a polymer of acrylicacid, an acrylic ester, acrylonitrile, acrylamide, co-polymers thereofor mixtures thereof, wherein said material for decreasing friction is asolid lubricant, wherein said solid lubricant is an inorganic compound,carbon or metal that provides barrier-layer lubrication, and mixturesthereof, and wherein said material for decreasing friction optionallycontains a lubricant additive, wherein said lubricant additive is anantioxidant, rust inhibitor, antiwear compound, extreme pressureadditive, detergent, dispersant, pour point depressant, viscosity-indeximprover, or foam inhibitor.
 5. The lubricant composition of claim 4,wherein said solid lubricant is graphite, molybdenum disulfide, cobaltchloride, antimony oxide, niobium selenide, tungsten disulfide, mica,boron nitride, silver sulfate, cadmium chloride, cadmium iodide, borax,basic white lead, lead carbonate, lead iodide, asbestos, talc, zincoxide, carbon, babbitt, bronze, brass, aluminum, gallium, indium,thallium, thorium, copper, silver, gold, mercury, lead, tin, indium, orthe Group VIII noble metals or mixtures thereof.
 6. The lubricantcomposition of claim 2 consisting essentially of a product produced bythe process of combining a superabsorbent polymer with a material fordecreasing friction between moving surfaces, wherein said superabsorbentpolymer absorbs greater than about 100 times its weight in water and isa polymer of acrylic acid, an acrylic ester, acrylonitrile, acrylamide,co-polymers thereof or mixtures thereof, wherein said material fordecreasing friction is a solid organic lubricant, and wherein saidmaterial for decreasing friction optionally contains a lubricantadditive, wherein said lubricant additive is an antioxidant, rustinhibitor, antiwear compound, extreme pressure additive, detergent,dispersant, pour point depressant, viscosity-index improver, or foaminhibitor.
 7. The lubricant composition of claim 6, wherein said solidorganic lubricant is a fluoroalkylene homopolymer or copolymer, a loweralkylene polyolefin homopolymer or co-polymer, a paraffinic hydrocarbonwax, phenanthrene, copper phthalocyanine, or mixtures thereof.
 8. Thelubricant composition of claim 2 consisting essentially of a productproduced by the process of combining a superabsorbent polymer with amaterial for decreasing friction between moving surfaces, wherein saidsuperabsorbent polymer absorbs greater than about 100 times its weightin water and is a polymer of acrylic acid, an acrylic ester,acrylonitrile, acrylamide, co-polymers thereof or mixtures thereof,wherein said material for decreasing friction is water containing alubricant additive, wherein said lubricant additive is an antioxidant,rust inhibitor, antiwear compound, extreme pressure additive, detergent,dispersant, pour point depressant, viscosity-index improver, or foaminhibitor.
 9. The lubricant composition of claim 2, consistingessentially of a product produced by the process of combining asuperabsorbent polymer with a material for decreasing friction betweenmoving surfaces, wherein said superabsorbent polymer absorbs greaterthan about 100 times its weight in water and is a polymer of acrylicacid, an acrylic ester, acrylonitrile, acrylamide, co-polymers thereofor mixtures thereof, wherein said material for decreasing friction is anoil or greases thereof and water, optionally containing a lubricantadditive, wherein said lubricant additive is an antioxidant, rustinhibitor, antiwear compound, extreme pressure additive, detergent,dispersant, pour point depressant, viscosity-index improver, or foaminhibitor.
 10. The lubricant composition of claim 2, consistingessentially of a product produced by the process of combining asuperabsorbent polymer with a material for decreasing friction betweenmoving surfaces, wherein said superabsorbent polymer absorbs greaterthan about 100 times its weight in water and is a polymer of acrylicacid, an acrylic ester, acrylonitrile, acrylamide, co-polymers thereofor mixtures thereof, wherein said material for decreasing friction is asolid lubricant and water, optionally containing a lubricant additive,wherein said lubricant additive is an antioxidant, rust inhibitor,antiwear compound, extreme pressure additive, detergent, dispersant,pour point depressant, viscosity-index improver, or foam inhibitor. 11.The lubricant composition of claim 10, wherein said solid lubricant isgraphite, molybdenum disulfide, cobalt chloride, antimony oxide, niobiumselenide, tungsten disulfide, mica, boron nitride, silver sulfate,cadmium chloride, cadmium iodide, borax, basic white lead, leadcarbonate, lead iodide, asbestos, talc, zinc oxide, carbon, babbitt,bronze, brass, aluminum, gallium, indium, thallium, thorium, copper,silver, gold, mercury, lead, tin, indium, the Group VIII noble metals, afluoroalkylene homopolymer or copolymer, a lower alkylene polyolefinhomopolymer or co-polymer, a paraffinic hydrocarbon wax, phenanthrene,copper phthalocyanine, or mixtures thereof.
 12. The lubricantcomposition of claim 2 consisting essentially of a product produced bythe process of combining a superabsorbent polymer with a material fordecreasing friction between moving surfaces, wherein said superabsorbentpolymer absorbs greater than about 100 times its weight in water and isa polymer of acrylic acid, an acrylic ester, acrylonitrile, acrylamide,co-polymers thereof or mixtures thereof, wherein said material fordecreasing friction is a phosphate, and wherein said material fordecreasing friction optionally contains a lubricant additive, whereinsaid lubricant additive is an antioxidant, rust inhibitor, antiwearcompound, extreme pressure additive, detergent, dispersant, pour pointdepressant, viscosity-index improver, or foam inhibitor.
 13. Thelubricant composition of claim 12, wherein said material for decreasingfriction is zinc phosphate, iron phosphate or manganese phosphate, ormixtures thereof.
 14. The lubricant composition of claim 2 consistingessentially of a product produced by the process of combining asuperabsorbent polymer with a material for decreasing friction betweenmoving surfaces, wherein said superabsorbent polymer absorbs greaterthan about 100 times its weight in water and is a polymer of acrylicacid, an acrylic ester, acrylonitrile, acrylamide, co-polymers thereofor mixtures thereof, wherein said material for decreasing friction is afatty oil, fatty acid, or wax, or mixtures thereof and wherein saidmaterial for decreasing friction optionally contains a lubricantadditive, wherein said lubricant additive is an antioxidant, rustinhibitor, antiwear compound, extreme pressure additive, detergent,dispersant, pour point depressant, viscosity-index improver, or foaminhibitor.
 15. The lubricant composition of claim 2 consistingessentially of a product produced by the process of combining asuperabsorbent polymer with a material for decreasing friction betweenmoving surfaces, wherein said superabsorbent polymer absorbs greaterthan about 100 times its weight in water and is a polymer of acrylicacid, an acrylic ester, acrylonitrile, acrylamide, co-polymers thereofor mixtures thereof, wherein said material for decreasing friction is asynthetic oil lubricant, or grease thereof, and wherein said materialfor decreasing friction optionally contains a lubricant additive,wherein said lubricant additive is an antioxidant, rust inhibitor,antiwear compound, extreme pressure additive, detergent, dispersant,pour point depressant, viscosity-index improver, or foam inhibitor. 16.The lubricant composition of claim 2 consisting essentially of a productproduced by the process of combining a superabsorbent polymer with amaterial for decreasing friction between moving surfaces, wherein saidsuperabsorbent polymer absorbs greater than about 100 times its weightin water and is a polymer of acrylic acid, an acrylic ester,acrylonitrile, acrylamide, co-polymers thereof or mixtures thereof,wherein said material for decreasing friction is a soap, and whereinsaid material for decreasing friction optionally contains a lubricantadditive, wherein said lubricant additive is an antioxidant, rustinhibitor, antiwear compound, extreme pressure additive, detergent,dispersant, pour point depressant, viscosity-index improver, or foaminhibitor.